Colorado State Publications Blog

How Geology Helped Build the Moffat Road

Our library recently received a fascinating new document for our collection that will be of interest to historians researching Colorado’s railroads as well as to those interested in our state’s geology and mineral resources.

Exactly one hundred years ago, in 1918, a special committee of the Denver Civic and Commercial Association asked State Geologist Russell George to produce a report of the mineral resources that could be found in the Northwest Colorado region of the Denver and Salt Lake Railroad, known informally as the “Moffat Road.” The committee, led by Denver Tramway Company president William Gray Evans, was interested in “the extent and location of the deposits of coal, oil shales, hydrocarbons, and other minerals of economic value…to be used by [the] Committee to make clear the public advantage and public necessity for the completion of the Denver and Salt Lake Railroad — the “Moffat Road” — and its main range tunnel.” In other words, Evans — one of the major promoters of the Moffat Tunnel after the 1911 death of its namesake, David Moffat — wanted to use this report as justification for the railroad and tunnel through the mountains, construction of which would be no easy task.

George and the Colorado Geological Survey provided Evans and his colleagues with a thorough description of the area’s resources, the most prominent being coal — the mining of which was one of the state’s major industries during this era. George’s narrative is bound together with three large foldout maps. One map shows the Road’s route and proposed tunnel location alongside existing (supposedly inadequate) rail lines. The second map details the area’s coal resources, and the third map points out locations of other mineral resources, including copper, molybdenum, tungsten, carnotite, gold, and oil and gas.
Evans and his colleagues were likely very pleased with the report, because George concluded that “the industrial value of many million dollars’ worth of useful mineral deposits depends largely upon the quick completion of the railroad enterprise, including the proposed tunnel through the main range.” However, it would be nearly a decade before the Moffat Tunnel finally opened in 1927. Evans didn’t live to see the tunnel’s completion; he died in 1924.

This document is an incredible primary source for anyone researching Colorado’s railroad history. Although it is not presently available online (the large size of the maps would make this difficult), anyone is welcome to come and view the document here in our library. Search our library’s online catalog for many more resources on Colorado’s history, geology, and transportation.

A D&SL train near Kremmling in 1928. Photo by Otto Perry courtesy of Denver Public Library Western History & Genealogy Department.
Colorado State Publications Blog

Is Your House on Shaky Ground?

Ground subsidence problems are very real in Colorado. Whether from naturally occurring elements in the soil or from the effects of Colorado’s mining history, the ground in certain parts of Colorado is susceptible to settling, collapsing, expanding, heaving, or swelling, all of which can have potentially hazardous effects on structures. So how do you know if your area is affected by subsidence and swelling soils? And if it is, what should you do?
When the Ground Lets You Down, a title in the Colorado Geological Survey’s popular Rock Talk series, provides an excellent introduction to these types of hazards. The geological processes are illustrated in simple diagrams and information is provided about insurance, emergency situations, and where to go for help.
Another helpful publication, produced especially for homeowners, is A Guide to Swelling Soils for Colorado Homebuyers and Homeowners. This helpful guidebook can be checked out from our library or through Prospector. 
Additional helpful resources available from our library include:

Also, search the term “geologic hazards” in our library’s online catalog for additional resources.

Colorado State Publications Blog

Time Machine Tuesday: Colorado Yule Marble

Lincoln Memorial.

Did you know that the Tomb of the Unknown Soldier and the Lincoln Memorial in Washington, D.C. are constructed of marble quarried here in Colorado? The stone comes from the Colorado Yule Marble quarry in the Crystal River valley near Marble, between Aspen and Carbondale. Colorado Yule marble, named for nearby Yule Creek, is a special variety of marble found only in Colorado. Yule marble has been used in buildings and monuments across the United States. Here in Denver it’s also been used in many state government buildings, including the building that houses our library.

The Yule Marble quarry. Courtesy Colorado Geological Survey.

The Colorado Yule Marble Company was founded by Channing Meek in 1905, although marble had been discovered in the area as early as the 1870s. The town of Marble was founded in 1881. It was after the turn of the century, however, when marble became especially fashionable. With financial assistance from the Rockefellers, Meek spent $3 million establishing the quarry and building a power plant and a railroad to the quarry site through Marble, where the processing mill was located. During its first few years the operation employed nearly 900 workers, many of them Italian immigrants. “Colorado Marble and Building Stone is the Finest in the World,” proclaimed the 1909-10 report of the state’s Bureau of Labor Statistics in a profile of Yule Marble, which you can read online from our library.

In 1912 an avalanche destroyed the quarry, which is cut into a steep mountainside. It was soon rebuilt and back in operation. That summer, Meek, the founder and superintendent, was killed in a trolley accident in the quarry. The operation continued with new leadership, however, and between 1914 and 1916 supplied stone to Washington, D.C. for the Lincoln Memorial.

Over the next few years, fires, floods, the coming of WWI, and labor troubles tested the company. It was foreclosed and split into two companies and sold; however, in 1924 the two companies merged to form the Consolidated Yule Marble Company. It was sold again in 1928, and in 1930, it was chosen to provide the stone for the Tomb of the Unknowns. “The company was chosen because it had the only quarry capable of cutting a single block of marble large enough for the proposed design,” according to an article in the Colorado Encyclopedia.

Tomb of the Unknown Soldier.
A building in Los Angeles constructed of Colorado Yule Marble.

By 1941, demand for marble had decreased as cheaper building materials were being introduced and modernist styles favored steel and glass. The quarry was shut down in the fall of that year, just prior to America’s entry into WWII. During and after the war, the quarry site sat mostly vacant until 1990, when it was finally reopened. A series of different owners have operated the site since that time. In 2004, marble was declared the State Rock

If you’re out exploring the Crystal River valley this summer, you can visit the Colorado Yule Marble site. While the quarry itself is closed to tourists, you can still hike near the old Crystal Mill and see scattered marble remnants and rejects. The town of Marble also has a history museum.

Marble remnants can still be seen while hiking around the area. Photo by Alan Levine courtesy Wikimedia Commons.

Colorado State Publications Blog

Time Machine Tuesday: "Mineral and Water Resources of Colorado," 1968

Fifty years ago Colorado’s two U.S. Senators, Gordon Allott and Peter Dominick, requested the State of Colorado and the U.S. Geological Survey to publish Mineral and Water Resources of Colorado“The importance of both of these vital resources to the economic well-being of Colorado cannot be overestimated,” Allott wrote in the report’s foreword.  “I requested its preparation for the purpose of making the significant data concerning Colorado’s mineral and water resources widely available to all.” Today, the report continues to be available to all, since it can now be read in digital format courtesy of our library.

Colorado Governor John Love, another sponsor of the report, wrote that “In offering this report to the citizens of Colorado, it is hoped that the report will be used as a quick reference for reliable information, and encourage greater development of our mineral and water resources.” This fervor for development of natural resources was challenged during the next few years as the environmental movement took hold. Candidates sensitive to environmental issues defeated both Allott and Dominick in the early 1970s.

A half a century later the report, prepared in cooperation by the U.S. Geological Survey, the Colorado Mining Industrial Development Board, and the Colorado Water Conservation Board remains a valuable reference listing out the natural resources of Colorado – the state’s geology and topography; the types of minerals that exist in the state; a history of oil and gas exploration; and more. The report is also an important primary source document regarding the history of natural resource development in Colorado. For numerous other documents on the history of Colorado’s natural resources, their development, and their conservation, search our library’s online catalog.


Colorado State Publications Blog

Time Machine Tuesday: Uranium Mining

Uranium was discovered in southwestern Colorado in the late nineteenth century.  It comes from carnotite ore, which also produces vanadium.  When these elements were first mined, vanadium was considered to be the more valuable of the two; it was used as an alloy to strengthen steel.  In 1921 the Colorado Geological Survey issued Radium, Uranium, and Vanadium Deposits of Southwestern Colorado, an excellent resource for understanding the early development of the industry prior to the nuclear age.

By the mid-twentieth century, during WWII and especially during the Cold War, uranium was highly sought after by the military for its use in the development of nuclear weapons.  Most of Colorado’s uranium extraction took place in what is known as the Uravan Mineral Belt, located primarily in Montrose and San Miguel counties.  Uranium extraction produced a yellowish substance resembling a cake mix, so the mill towns that developed were nicknamed “yellowcake towns.”  (Check out from our library the book Yellowcake Towns:  Uranium Mining Communities in the American West, published by University Press of Colorado, for more information).  Examples of yellowcake towns in Colorado included Naturita, Nucla, Paradox, Slick Rock, and Uravan.  Uranium has also been mined in other parts of the state as well.

Uranium mining became one of Colorado’s major industries in the Cold War era; according to the Colorado Encyclopedia, 63 million pounds of uranium were produced in the Uravan Mineral Belt between 1948 and 1978.

Eventually, the decades of radium, uranium, and vanadium extraction began taking a toll on the environment.  In 1971 the State published Uranium Wastes and Colorado’s Environment, which exposed many of the problems caused by uranium mining.  Colorado’s Involvement with Uranium Mill Tailings, published in 1976, also explored this issue.  Both reports are available online via our library.

The impact on public health was also a growing concern.  A linkage between uranium mining and the development of cancer in mine workers became apparent, and in 1990 Congress passed the Radiation Exposure Compensation Act.  These health concerns, alongside new environmental regulations and the availability of cheaper uranium from other countries, caused Colorado’s uranium industry to bust.  By the early 2000s, however, development of new radioactive waste disposal facilities caused a resurgence in interest in uranium.  (See Uranium, It’s Hot!! And Back by Popular Demand, part of the Colorado Geological Survey’s Rock Talk series.) 

Further resources on uranium available from our library include:

Colorado State Publications Blog

Colorado Coal Resources

Coal is one of Colorado’s most significant mineral resources, and over the years has played an important part in our state’s history and economy.  You can learn about Colorado coal in numerous publications available from our library.  Some highlights from our collection include

General resources:


Inactive/abandoned mines:

Industry information:


  • The Archaeology of Class War:  The Colorado Coafield Strike of 1913-1914, 2009
  • Coal People:  Life in Southern Colorado’s Company Towns, 1890-1930, 1999
  • From Redstone to Ludlow:  John Cleveland Osgood’s Struggle Against the United Mine Workers of America, 2009
  • The Great Coafield War, 2009
  • High Altitude Energy:  A History of Fossil Fuels in Colorado, 2002
  • Industrializing the Rockies:  Growth, Competition, and Turmoil in the Coalfields of Colorado and Wyoming, 1868-1914, 2003
  • “Remember Ludlow!”, 1999
  • Routt and Moffat Counties, Colorado, Coal Mining Historic Context, 1991
  • When Coal Was King:  A History of Crested Butte, Colorado, 1880-1952, 1999


Safety and inspection:




Colorado State Publications Blog

All About Pikes Peak

Pikes Peak as seen from Garden of the Gods.  Photo courtesy Colorado Tourism Office.

Without a doubt, it’s Colorado’s most famous mountain.  And while it’s neither the tallest mountain in Colorado nor the most difficult to scale, Pikes Peak is famous for its visibility from the plains, its use as a symbol of the 1859 Colorado Gold Rush, and for the legendary explorer for whom it is named.

Zebulon Montgomery Pike, a U.S. Army soldier, arrived in present-day Colorado in 1806 to explore the lands that were now a part of the United States as a result of the Louisiana Purchase.  Pike and his men were assigned to search out the source of the Arkansas River.  While on this expedition, Pike spotted what he described as a “small blue cloud” in the distance.  This “cloud” turned out to be the peak that would be named in his honor.  Pike and his men wintered in the area at what came to be known as Pike’s Stockade, and during the long winter Pike set out to explore the peak that had captured his interest.  Perhaps due to the heavy snows, Pike never did climb his peak; fourteen years later, a member of Stephen Long’s Expedition named Edwin James became to be the first to climb it, so the mountain became known as James Peak for a time.*  However, when settlers began pouring into Colorado in the 1850s in search of gold, the mountain was renamed for its early admirer and became a symbol of the Gold Rush.  In fact, “Pike’s Peak or Bust” became the rallying cry for the gold seekers.

According to official rankings, Pikes Peak is Colorado’s 30th highest mountain, at 14,110 feet.  Colorado has 53 “fourteeners.”  The spelling of the name can be confusing.  Since 1890 Pikes Peak has officially been spelled without the possessive apostrophe.  The U.S. Board of Geographic Names has removed nearly all apostrophes from place names for uniformity and ease of signage.  Colorado’s Longs Peak also lacks the apostrophe.

Pikes Peak is also a major tourist attraction.  Visitors not only can hike up the mountain, but also have the option of driving up or taking the famous Pikes Peak Cog Railway.  Pikes Peak and nearby mining towns also make up the Gold Belt Tour Scenic & Historic Byway.

In our library you can find many resources relating to the history, geology, and biology of Pikes Peak.  Resources listed below without hyperlinks can be checked out in print.

For biographical resources on Zebulon Pike, see the following:

  • The Death of Zebulon Pike,” by Robert M. Warner, Colorado Magazine, April 1955.
  • “Pike and His Peak,” by Judith Gamble, Colorado Heritage, Issue 3, 1989
  • Where is Zebulon Montgomery Pike Buried?” by Albert W. Thompson, Colorado Magazine, July 1936.
  • Zebulon Montgomery Pike,” by LeRoy R. Hafen, Colorado Magazine, July 1931.
  • “Zebulon Pike in Southern Colorado:  A Photo Travelogue,” by Michael Wren, Colorado Heritage, Winter 2006.   

For resources on the Pikes Peak Gold Rush, see

To learn about the natural resources of Pikes Peak the surrounding area see

For resources on Pike’s Stockade, see

    For other historical information, see

    • History of Colorado, by LeRoy R. Hafen, State Historical and Natural History Society, 1927.
    • The Naming of Pike’s Peak,” by Raymond Calh
      oun, Colorado Magazine, April 1954.
    • “Through a Glass Sharply:  Edwin James and the First Recorded Ascent of Pikes Peak, July 13-15, 1820,” by Phil Carson.  Essays and Monographs in Colorado History, n. 14, 1994.

    Additionally, mini-biographies of Zebulon Pike, Julia Archibald Holmes (first woman to summit Pikes Peak), and Daniel Cheesman Oakes (goldseeker and Pikes Peak guidebook author), are available from Colorado Virtual Library.  Also be sure to check the Colorado Encyclopedia for articles.

    *The Arapaho Indians called it Long Mountain, and Spanish explorers knew it as El Capitán.

    Colorado State Publications Blog

    Time Machine Tuesday: Leadville Metals Exposure Study

    Leadville is one of Colorado’s most historic mountain towns.  Though a small mountain town today, in the 1870s and 1880s Leadville rivaled Denver for the state’s most prestigious city and many millionaires were made through Leadville’s silver mines.  Following the Crash of 1893, most of Leadville’s silver mines were abandoned, although other mining activities such as molybdenum mining did continue in Leadville through the twentieth century.
    Because of the sheer volume of mining near Leadville, the entire town is included in the 18-square-mile California Gulch superfund site.  While much of the site has been cleaned up, there is still continual monitoring of the site and cleanup of some areas is still ongoing.  Much of the cleanup work began after the Colorado Department of Public Health & Environment and federal partners undertook a major study of the area in 1990.
    The Leadville Metals Exposure Study, available digitally from our library, reported that “soil surveys done in connection with a remedial investigation of [the site] found elevated levels of lead (Pb), arsenic (As), and Cadmium (Cd) in surface soils in residential areas.  A study of heavy metal exposure to individuals living in Leadville, Colorado is described in this report.”  The report especially focused on the exposure of children to toxic lead.  “Studies have linked lead in the blood of children to lead in dust on children’s hands to lead in floor and sill dust in houses and to lead in the soil outside the children’s houses.”  The study presents detailed data on the lead exposure to humans in Leadville, including comparisons to other places in the United States.
    The following year, another study, this one by the Colorado Water Resources Research Institute at Colorado State University, measured the effects of the metal contamination on the water quality in the California Gulch site.  Entitled Fate and Effects of Heavy Metals on the Arkansas River, this publication is also available online from our library.
    Twenty-five years later, the site is still undergoing remediation.  The EPA website reports that the “human exposure status” is still “not under control,” although the “contaminated ground water status” has been controlled.  For more documents relating to mining, hazardous waste, and public health, search our library’s online catalog.

    The effects of mining are visible in this EPA photo of the California Gulch superfund site.
    Colorado State Publications Blog

    Time Machine Tuesday: The White Ash Mine Disaster

    This fall the Colorado School of Mines unveiled a new memorial dedicated to the victims of the White Ash Mine disaster of 1889.  Ten miners lost their lives in the accident near Golden, Colorado.

    The White Ash Mine was located adjacent to the Loveland Mine, which had been shut down in 1881 following a fire.  The fire had damaged the 90-foot pillar that separated the two mines.  Meanwhile, water from nearby Clear Creek had been seeping into the Loveland Mine, and after eight years the damaged pillar finally broke, unleashing water into the White Ash Mine and drowning ten workers.

    In the 1889 report of the State Coal Mine Inspector, which is available online through our library, inspector John McNeil recounts how he immediately responded to the disaster, which had occurred at about 4pm on September 9, 1889.  In attempting a rescue effort, he found that water had reached a height of 100 feet above the shaft, making survival impossible.  McNeil and White Ash foreman Evan Jones and mine manager Paul Lanius worked all night in the hope of reaching some survivors.  Water was not the only deadly issue they had to contend with, however.  “By three o’clock on the morning of the tenth instant, I lowered a light with a hand line to a depth of 530 feet, at which point it was extinguished by the carbonic acid gas.”  McNeil was also “astonished to find that the water had a temperature of 115 degrees Fahrenheit.”  McNeil and Jones descended the mine in a bucket with a hoisting cable.  They “found that a portion of the old workings on this level were on fire, and judging from the intense heat…felt satisfied that the fire itself would soon reach the shaft timbers, [which were] already smoking.”  Coming back up to the surface, McNeil ordered the two mines be sealed up in order to keep the fire from spreading.  Later in the month the mines were reopened and water pumping and debris clearing began, which took several months.  It was during this cleanup period that the bodies of the ten men were found.

    The 1889 report is of enormous historical value relating to this incident, because it not only gives us McNeil’s eyewitness account, but also contains copies of correspondence; information on the investigation; a fold-out illustration of the underground workings of the mine, showing the conditions for the accident; and a list of the names of the deceased.  All other mine fatalities occurring that year are also listed in the report.

    Starting in 2009, Golden citizens and civic organizations raised money for the memorial statue, which replaced a small memorial plaque that had been dedicated in 1936 by Golden Mayor Albert Jones, son of foreman Evan Jones. Colorado School of Mines donated the land for the new memorial, which was dedicated on October 29, 2016.

    The new memorial commemorating the White Ash Mine disaster.  Photo courtesy Colorado School of Mines.

    Colorado State Publications Blog

    Time Machine Tuesday: Oil Shale

    In 1921 the Colorado Geological Survey published a bulletin entitled Oil Shales of ColoradoAccording to the report, Pennsylvania and nearby states dominated the petroleum extraction industry in the mid-nineteenth century, but as drilling declined at the same time that demand increased, Colorado and other western and mid-western states looked to Scotland and France, who had all the while been experimenting with oil shale.

    What is oil shale?  Oil shale is oil that is produced by distillation of sedimentary rock.  For an easy-to-understand explanation, see the Colorado Geological Survey’s 2004 RockTalk publication about “black gold.”

    Oil shale production, Colorado, 1918.

    Looking back to 1921, however, it was clear that with the increase in automobile production and sales, more oil would be needed.  The recent war had also caused increased demand.  “When the ever-increasing demand is taken into consideration,” writes report author R.D. George, “it is evident that the time is not far distant when a part of the supply will again come from the distillation of shales.  When that time comes Colorado will unquestionably take a prominent place.”

    Did George accurately predict the future of oil shale?  In some ways, yes — oil shale continues to be experimented with in Colorado.  However, as stated in the above-referenced RockTalk article, although oil shale has enormous potential, “the United States is not using this apparently vast resource to any significant extent, and it may not be able to do so in the near future.”  Why?  Processing is very expensive, says the article, and not always environmentally friendly:  “…at present, the economical way to mine it appears to be surface- or strip-mining with its associated land disturbance.  Most of the richest oil shale is located in areas of the western United States that are chronically short of water, making revegetation after strip-mining difficult.”  The water shortage is another problem, as oil shale production requires significant amounts of water.  Economics are also a factor, as described in the article.

    Despite its challenges, oil shale development has a significant role in the history of Colorado resource extraction.  Check out the 1921 publication and others from our library to learn more about the history of oil shale in Colorado.

    Photo courtesy U.S. Geological Survey.

    Colorado State Publications Blog

    Time Machine Tuesday: Molybdenum

    When most people think of Colorado mining, they think of gold or silver, or maybe coal.  But one of Colorado’s most significant mineral resources of the past century is molybdenum.  Today, however, demand for “moly” is declining.  Plans were recently announced to shutter Clear Creek County’s huge Henderson Mine — the world’s largest primary producer of moly, according to their website.  The Henderson underground mine is owned by the same company that owns the Climax Mine, an open-pit moly mine.  Over the past century, demand for moly has fluctuated, with the Climax Mine closing and reopening several times.

    What is molybdenum, and how is it used?  Moly, for short, is used as an alloy in steel production.  Its usefulness as an alloy is due to it having a higher melting point than iron.  The Climax Mine began production in 1914.  After the U.S. entered the war in 1917, demand for moly rose sharply due to its use in the production of war matériel; however, at the end of the war, the mine shut down when demand was reduced.  It reopened in 1924, shut down in 1995, and reopened in 2012.  During its heyday during mid-century, Climax had been its own town, with schools, housing, a post office, and a railroad station.  Most of the houses were moved to nearby Leadville in 1965.

    The Climax Molybdenum Mine. Photo attribution: By JERRYE AND ROY KLOTZ MD (Own work) [CC BY-SA 3.0 (], via Wikimedia Commons
    In 1919, the Colorado Geological Survey produced a report examining the industry.  Molybdenum Deposits of Colorado: With General Notes on the Molybdenum Industry was the resulting report from a research analysis of moly that had started during the war.  “Soon after it was declared that a state of war existed between the United States and Germany, the Colorado Geological Survey was asked to cooperate with Federal officials in determining the extent of the undeveloped molybdenum resources of Colorado,” wrote the report’s author, P.G. Worcester.

    This report includes analysis of the history, use, and chemical properties of moly along with a review of moly deposits across the state.  Moly deposits in countries such as Australia, Canada, Germany, and Norway are also examined, as is an analysis of the predicted future of the industry.  Because the report had been commissioned during the war but was not produced until 1919, after its completion (and the same year the Climax Mine closed the first time), the report had begun with optimism for the industry but ended on a much different note.  “From what has been said in the preceding pages it is evident that, at the present time, the outlook for a rapidly expanding industry is none too bright…It is the writer’s belief that the demand will increase slowly as successful metallurgical experiments develop new uses or improved uses for the metal,” wrote Worcester.

    Want to learn more about moly? In 2001, the Colorado Geological Survey produced an entry in their “Rock Talk” series entitled Unsinkable Moly:  Colorado’s World-Class Metal ResourceThis pamphlet describes in plain language the uses, geology, and history of moly in Colorado as well as its two major moly mines.  For more on Colorado’s geology and mining history, search our library’s online catalog and digital repository.

    Colorado State Publications Blog

    Fracking: Risk to Homes and the Environment

    Today’s Denver Post headlined “Colorado residents push to protect homes, river from fracking,” which discusses the use of state rules that were established by recommendations from a 2014 task force.  If you’re looking for the task force’s report, which does not appear to be linked to in the Post article, you can find it here.  For further resources, search the term “hydraulic fracturing” in our library’s web catalog.

    Colorado State Publications Blog

    Time Machine Tuesday: Diamonds in Colorado

    Did you know that Larimer County had a diamond mine?  The Kelsey Lake Mine was operational from 1996 to 2001.  During that time period, in 1999, the Colorado Geological Survey released What Are Diamonds?, an issue of their popular Rock Talk series.  This publication discussed Northern Colorado’s State Line Kimberlite District and the Kelsey Lake Mine, as well as the history of diamond mining in Colorado and the geology of diamonds.  In this fun, easy-to-read publication, you can learn such fun facts as:

    • How do volcanic deposits form diamonds?
    • What is Colorado’s connection to the famous Hope Diamond?
    • What was the Great Diamond Hoax of 1872?
    • How are diamonds mined?
    • What was the largest diamond found in Colorado?

    For current information, including a location map, visit the Colorado Geological Survey’s Diamonds webpage.

    Colorado State Publications Blog

    Time Machine Tuesday: Oil and Gas Fields of Colorado

    Most Coloradans know that oil and gas production has skyrocketed in Colorado, but a 1975 resource from the Colorado Geological Survey illustrates the industry’s development visually and using statistics.  Oil and Gas Fields of Colorado includes two parts:  a map, and a book of statistical data.  You can see how much the industry has expanded by comparing the 1975 map to a current map courtesy of the Colorado Oil and Gas Conservation Commission.  COGCC also has data files to compare with the 1975 statistics.

    Oil and gas fields, 1975
    Oil and gas fields today
    Colorado State Publications Blog

    Volcanoes and Volcanic Activity

    Volcanoes in Colorado?

    While we don’t have volcanoes in Colorado today, volcanoes certainly played a role in the geological formation of the area.  Evidence of volcanoes can be found as close to Denver as Dinosaur Ridge.  In the Colorado Geological Survey’s Dinosaurs in Our Backyard:  A Dynamic Visit to Dinosaur Ridge, Fossil Trace and Red Rocks – Interactive CD-Rom and Audio Tour, available for checkout from our library, the narrator describes the evidence of volcanoes at this prehistory-rich site just west of Denver:

    During the deposition of the Dakota formation, volcanoes north and west of here were spewing ash into the Colorado sky.  A layer of white ash from one of these volcanic eruptions is visible at this site.  This ash contained radioactive uranium elements, which slowly changed to lead over time.  By comparing the ratio of radioactive uranium to lead today, scientists from the United States Geological Survey were able to determine the age of the ash and the surrounding rock layers to be 106 million years old.

    The San Juan Mountains of southwestern Colorado also show evidence of volcanic activity.  This is described in a chapter of the University Press of Colorado book The Western San Juan Mountains:  Their Geology, Ecology, and Human History, also available for checkout from our library.  “The San Juan volcanic field is part of a much larger volcanic region that was active throughout the Southern Rocky Mountains from about 40 million to 18 million years ago.  The volcanic activity…produced lavas and pyroclastic debris that covered all of south-central Colorado and the north-central part of New Mexico,” according to the book.

    Colorado’s neighboring states have even more significant associations with volcanic activity.  New Mexico is home to the large Valles Caldera, which you can read about in the Colorado Geological Survey’s Field Trip Guide to the Quaternary Valles Caldera and Pliocene Cerros del Rio Volcanic FieldThe most likely place for a volcano to occur in the future near Colorado, however, is to the north of us, in Yellowstone National Park which is known for its geothermal activity. 

    Colorado State Publications Blog

    Time Machine Tuesday: 1882 Colorado Earthquake

    Earthquakes in Colorado?  Yes, earthquakes are certainly possible in Colorado, and on November 7, 1882, Colorado was hit by an earthquake thought to be centered in the northern Front Range.  A century later, in 1986, the Colorado Geological Survey published a report, An Interpretation of the November 7, 1882 Colorado Earthquake by Robert M. Kirkham and William P. Rogers.  The report stated that “this earthquake was probably the largest to occur in Colorado during the period of historic record.  A similar-sized event today could have significant impact on modern structures, possibly causing serious property damage and perhaps injury or death.”  The report analyzes the historic writings of the time, including newspaper articles, to get an idea of the intensity of the earthquake.  It speculates on how the event was covered in the press — or not.  Finally, the report draws conclusions about the earthquake’s causes.

    You can find more resources on Colorado earthquakes by searching our library’s web catalog

    Colorado State Publications Blog

    Time Machine Tuesday: Colorado Rocks and Minerals

    Back in 1913, mining played an important role in Colorado’s economy and employed thousands of workers.  Hundreds more were made wealthy by owning and investing in Colorado’s mines.  Therefore it is no surprise that in that year the Colorado Geological Survey published a book entitled Common Rocks and Minerals:  Their Occurrence and UsesAs suggested in its title, this book explores the numerous types of rocks and minerals available in Colorado and, tangentially, how money could be made from them.  It provides information on all types of rocks and minerals, from gemstones to metallic minerals to stones useful in the building trade.  “Many valuable minerals lie unused for want of knowledge of what they are and how they may be used.  It is hoped that [this book] will stimulate an interest in, and a search for, valuable geological products,” the book explains, demonstrating the importance of minerals to the state’s economy and the continued opportunities available to exploit those resources in the early part of the twentieth century.

    Underground inside the Yule marble quarry in Pitkin County.  Photo courtesy Colorado Geological Survey.
    Colorado State Publications Blog

    Time Machine Tuesday: First Report of the Colorado Geological Survey, 1908

    The very first report of the Colorado Geological Survey covered the activities of the year 1908.  In addition to giving some information on the geological landscape of Colorado, the report also offers a history of the agency up to that time.  According to the report, the Territorial Legislature had established the office of State Geologist back in 1872; the first person to hold that position was J. Alden Smith.  The laws of the territory signified that the State Geologist would serve a two-year position without compensation.  The Geological Survey itself was created by an act of the Legislature in 1907.  They established an Advisory Board and allocated $5000 to the survey per year.  The report describes the agency’s field work, maps, library, and plans for the future.  The remainder of the report includes specific discussions on survey work including tungsten in Boulder; mining in Summit County; the Foothills Formation in northern Colorado; and a survey of the Hahns Peak Region in Routt County.

    For many years the Colorado Geological Survey was located within the Colorado Department of Natural Resources.  Currently it resides with the Colorado School of Mines.  In 1988 the state published a History of the Colorado Geological Survey that discusses the agency’s history including research accomplishments, staffing, and mineral resources.  The CGS-published book Messages in Stone:  Colorado’s Colorful Geology also includes some historical information on the organization.  Search our library’s web catalog for additional publications from the Colorado Geological Survey. 

    Colorado State Publications Blog

    Time Machine Tuesday: Oil and Gas in Colorado, 1925

    Where was oil found in Colorado in the early days of the automobile?  How do different parts of the state compare in oil and gas production based on geological epochs?  A 1925 map (reprinted in 1984) from the Colorado Geological Survey answers these questions and more.  Although the early map did not use color, it instead used shading to indicate the various geological time periods (Tertiary, Cretaceous, Triassic/Jurassic, Paleozoic) and symbols to indicate oil fields, gas and oil seeps, anticlines, bitumen, deep water wells, and other relevant information.  This interesting look into the early years of oil and gas production has been digitized and is available online from our library.  Visit our web catalog for further resources.

    Colorado State Publications Blog

    Colorado Points of Interest

    As you travel through Colorado, you will find numerous markers designating points of interest.  Some of these are historical, and others geological.

    Historical – History Colorado (formerly the Colorado Historical Society) places and maintains point of interest markers in places where important historical events occurred around the state.  Our library recently acquired an interesting Historical Society publication done in 1972.  Entitled Point of Interest, it is a pictorial guide with stories, maps, photos, and drawings of historical sites, divided by region.  While the sites covered in the book can still be visited, of course, many new sites and markers have been added since then.  And the technology has changed, too — no longer do you need to flip through a guidebook.  History Colorado now offers a Historic Marker Database that you can access with your mobile device as you drive around the state, or view online as you plan your trip. 

    Geological – Even before history was prehistory, and the changes in the earth over the eons can be easily seen from your car window as you drive through Colorado.  The Colorado Geological Survey provides an interactive map for finding points of geological interest, or POGIs, such as mines, fossils, caves, and rock formations.  Click on a POGI on the map to see photos and read an explanation of the POGI’s geological significance.  You can also read about the POGI program in the Spring 2006 issue of RockTalk, available from our library.

    Points of interest can be fun ways to keep the kiddos entertained during road trips, or for anyone to learn about the special places that make Colorado what it is.

    Colorado State Publications Blog

    Oil and Gas Resources

    One of the specialties of the University of Colorado Law School is natural resources law, and the School’s Getches-Wilkinson Center for Natural Resources, Energy, and the Environment is sponsoring the Intermountain Oil and Gas BMP Project.  The Project’s website features a helpful resources page on their website that includes information on oil and gas development, GIS, reclamation, hydraulic fracturing (or fracking), coalbed methane, air and water quality, effects on wildlife and vegetation, and much more.  Each topic includes background articles and links on the topic.  This website is a great place to start for anyone researching the development, best management practices, and environmental effects of oil and gas in Colorado.