Front Range

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Front Range

Front Range Peaks seen from State Highway 72.
Highest point
Peak Grays Peak
Elevation 14,278 ft (4,352 m)
Coordinates 39°38′02″N 105°49′01″W / 39.63389°N 105.81694°W / 39.63389; -105.81694Coordinates: 39°38′02″N 105°49′01″W / 39.63389°N 105.81694°W / 39.63389; -105.81694
Geography
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The Front Range (excluding the Laramie Mountains) is shown highlighted on a map of the western U.S.
Country United States
States Colorado and Wyoming
Parent range Rocky Mountains

The Front Range is a mountain range of the Southern Rocky Mountains of North America located in the central portion of the U.S. State of Colorado and southeastern portion of the U.S. State of Wyoming.[1] It is the first mountain range encountered moving west along the 40th parallel north across the Great Plains of North America. The Front Range runs north-south between Casper, Wyoming and Pueblo, Colorado and rises nearly 10,000 feet above the Great Plains. Longs Peak, Mount Evans, and Pikes Peak are its most prominent peaks, visible from the Interstate 25 corridor. The area is a popular destination for mountain biking, hiking, climbing, and camping during the warmer months and for skiing and snowboarding during winter. Millions of years ago the present-day Front Range was home to ancient mountain ranges, deserts, beaches, and even oceans.[2]

The name "Front Range" is also applied to the Front Range Urban Corridor, the populated region of Colorado and Wyoming just east of the mountain range and extending from Cheyenne, Wyoming south to Pueblo, Colorado. This urban corridor benefits from the weather-moderating effect of the Front Range mountains, which help block prevailing storms.

Geology

Pikes Peak and Garden of the Gods.
Sandstone slabs along the eastern edge of the front range

Pikes Peak Granite

About 1 billion years ago, the earth was producing mass amounts of molten rock that would one day amalgamate, drift together and combine, to ultimately form the continents we live on today. In the Colorado region, this molten rock spewed and cooled, forming what we now know as the Precambrian Pikes Peak Granite. Over the next 500 million years, little is known about changes in the sedimentation (sediment deposition) after the granite was produced. However, at about 500 – 300 million years ago, the region began to sink and sediments began to deposit in the newly formed accommodation space. Eroded granite produced sand particles that began to form strata, layers of sediment, in the sinking basin. Sedimentation would continue to take place until about 300 million years ago.[2]

Fountain formation

Around 300 million years ago, the sinking suddenly reversed, and the sediment-covered granite began to uplift, giving rise to the Ancestral Rocky Mountains. Over the next 150 million years, during uplift the mountains would continue to erode and cover themselves in their own sediment. Wind, gravity, rainwater, snow, and ice-melt supplied rivers that ultimately carved through the granite mountains and eventually led to their end. The sediment from these mountains lies in the Fountain Formation today. Red Rocks Amphitheater outside of Denver, Colorado, is actually set into the Fountain Formation.[2]

Lyons Sandstone

At 280 million years ago, sea levels were low and present-day Colorado was part of the super-continent Pangaea. Sand deserts covered most of the area spreading as dunes seen in the rock record, known today as the Lyons Sandstone. These dunes appear to be cross-bedded and show various fossil footprints and leaf imprints in many of the strata making up the section.[2]

Lykins Formation

30 million years later, the sediment deposition was still taking place with the introduction of the Lykins Formation. This formation can be best attributed to its wavy layers of muddy limestone and signs of stromatolites that thrived in a smelly[citation needed] tidal flat at present-day Colorado. 250 million years ago, the Ancestral Rockies were burying themselves while the shoreline was present during the break-up of Pangaea. This formation began right after Earth’s largest extinction 251 million years ago at the Permian-Triassic Boundary. Ninety percent of the planet’s marine life was destroyed and a great deal on land as well.[2]

Morrison Formation

After 100 million years of deposition, a new environment brought rise to a new formation, the sandstone Morrison Formation. The Morrison Formation contains some of the best fossils of the Late Jurassic. It is especially known for its sauropod tracks and sauropod bones among other dinosaur fossils. As identified by the fossil record, the environment was filled with various types of vegetation such as ferns and Zamites.[2] While this time period boasts many types of plants, grass had not yet evolved.[2]

Dakota Sandstone

The Dakota Sandstone, which was deposited 100 million years ago towards Colorado’s eastern coast, shows evidence of ferns, and dinosaur tracks. Sheets of ripple marks can be seen on some of the strata, confirming the shallow-sea environment.[2]

Pierre Shale

Over the next 30 million years, the region was finally taken over the by a deep sea, the Cretaceous Western Interior Seaway, and deposited mass amounts of shale over the area known as the Pierre Shale. Both the thick section of shale and the marine life fossils found (ammonites and skeletons of fish and such marine reptiles as mosasaurs, plesiosaurs, and extinct species of sea turtles, along with rare dinosaur and bird remains). Colorado eventually drained from being at the bottom of an ocean to land again, giving yield to another fossiliferous rock layer, the Denver Formation. At about 68 million years ago, the Front Range began to rise again due to the Laramide Orogeny in the west.[2]

Denver Formation

Front Range near Estes Park, Colorado.

The Denver Formation contained fossils and bones from dinosaurs like Tyrannosaurus rex and Triceratops. While the forests of vegetation, dinosaurs, and other organisms thrived, their reign would come to an end at the Cretaceous–Paleogene boundary (which is also known as the K-T boundary). In an instant, millions of species are obliterated from a meteor impact in Mexico’s Yucatan Peninsula. While this extinction lead to the dinosaurs’ and other organisms’ demise, some life did prevail to repopulate the earth as it recovered from this tremendous disaster. The uplifted Front Range continued to constantly erode and, by 40 million years ago, the range was once again buried in its own rubble.[2]

Castle Rock Conglomerate

Suddenly, 37 million years ago, a great volcanic eruption took place in the Collegiate Range and covered the landscape in molten hot ash that instantly torched and consumed everything across the landscape. An entire lush environment was capped in a matter of minutes with 20 feet of extremely resistant rock, rhyolite. However, as seen before, life rebounds, and after a few million years mass floods cut through the rhyolite and eroded much of it as plants and animals began to recolonize the landscape. The mass flooding and erosion of the volcanic rock gave way to the Castle Rock Conglomerate that can be found in the Front Range.[2]

Quaternary deposits

Eventually, at about 10 million years ago, the Front Range began to rise up again and the resistant granite in the heart of the mountains thrust upwards and stood tall, while the weaker sediments deposited above it eroded away. As the Front Range rose, streams and recent (16,000 years ago) glaciations during the Quaternary age literally unburied the range by cutting through the weaker sediment and giving rise to the granitic peaks present today.[2] This was the last step in forming the present-day geologic sequence and history of today’s Front Range.[2]

The Front Range as viewed from Greenwood Village south of Denver, Mount Evans is on the far right

Prominent peaks

The Front Range includes the highest peaks along the eastern edge of the Rockies. The highest mountain peak in the Front Range is Grays Peak. Other notable mountains include Torreys Peak, Mount Evans, Longs Peak, Pikes Peak, and Mount Bierstadt.

Longs Peak
Pikes Peak
Mount Evans
The 20 Mountain Peaks of the Front Range With At Least 500 Meters of Topographic Prominence
Rank Mountain Peak Subrange Elevation Prominence Isolation
1 Grays Peak[3] NGS Front Range !B9916216092114 4352 m
14,278 ft		!B9932614968559 844 m
2,770 ft		!B9893966379461 40 km
25 mi
2 Mount Evans NGS Front Range !B9916225287517 4348 m
14,265 ft		!B9932618581689 844 m
2,769 ft		!B9903347696365 16 km
10 mi
3 Longs Peak NGS Front Range !B9916229888391 4346 m
14,259 ft		!B9932019345948 896 m
2,940 ft		!B9888410388702 70 km
44 mi
4 Pikes Peak NGS Pikes Peak Massif !B9916330926332 4302 m
14,115 ft		!B9925701563606 1686 m
5,530 ft		!B9885091156659 98 km
61 mi
5 Mount Silverheels NGS PB Front Range !B9916535951295 4215 m
13,829 ft		!B9934548543834 696 m
2,283 ft		!B9909152228509 8.8 km
5.5 mi
6 Bald Mountain[4] PB Front Range !B9916636562494 4173 m
13,690 ft		!B9935388834479 640 m
2,099 ft		!B9905998660563 12 km
8 mi
7 Bard Peak[4] PB Front Range !B9916668536928 4159 m
13,647 ft		!B9937491274770 518 m
1,701 ft		!B9909243345313 8.7 km
5.4 mi
8 Hagues Peak NGS PB Mummy Range !B9916722738335 4137 m
13,573 ft		!B9933965766360 738 m
2,420 ft		!B9898488714245 26 km
16 mi
9 North Arapaho Peak[4] PB Indian Peaks PB !B9916770782011 4117 m
13,508 ft		!B9937705190527 507 m
1,665 ft		!B9898822078448 25 km
15 mi
10 Parry Peak[4] Front Range !B9916853294400 4083 m
13,397 ft		!B9937316445209 528 m
1,731 ft		!B9903696343685 15 km
9 mi
11 Mount Richthofen[4] PB Front Range !B9917196006019 3946 m
12,945 ft		!B9932945273816 817 m
2,680 ft		!B9903488273760 16 km
10 mi
12 Specimen Mountain[4] PB Front Range !B9917550720665 3808 m
12,494 ft		!B9937316445209 528 m
1,731 ft		!B9910355601664 7.8 km
4.9 mi
13 Bison Peak NGS PB Tarryall Mountains PB !B9917600370258 3789 m
12,432 ft		!B9933838478039 747 m
2,451 ft		!B9896647300310 31 km
19 mi
14 Waugh Mountain[4] PB South Park Hills PB !B9918194242557 3571 m
11,716 ft		!B9934344759086 710 m
2,330 ft		!B9896196573432 32 km
20 mi
15 Black Mountain NGS PB South Park Hills PB !B9918251562823 3551 m
11,649 ft		!B9934765507692 681 m
2,234 ft		!B9905334682226 13 km
8 mi
16 Williams Peak NGS PB South Williams Fork Mountains PB !B9918276096485 3542 m
11,620 ft		!B9935629926271 625 m
2,049 ft		!B9902375001407 17 km
11 mi
17 Puma Peak[4] PB South Park Hills PB !B9918314996940 3528 m
11,575 ft		!B9934649793629 689 m
2,260 ft		!B9906098412014 12 km
7 mi
18 Thirtynine Mile Mountain[4] PB South Park Hills PB !B9918333821075 3521 m
11,553 ft		!B9935441381346 636 m
2,088 ft		!B9902543365326 17 km
11 mi
19 Twin Sisters Peaks[4] PB Front Range !B9918438794080 3485 m
11,433 ft		!B9934353352100 710 m
2,328 ft		!B9911449070199 7.0 km
4.4 mi
20 South Bald Mountain Laramie Mountains !B9918817929505 3355 m
11,007 ft		!B9936684981501 562 m
1,844 ft		!B9900016569164 22 km
14 mi

See also

References

  1. ↑ http://geonames.usgs.gov/pls/gnispublic | U.S. Geological Survey confirms that the Laramie Mountains(range) are the northern extent of the Front Range.
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.11 2.12 Johnson, Kirk R. et al. (2006). Ancient Denvers. Fulcrum Publishing. ISBN 978-1-55591-554-4. 
  3. ↑ The summit of Grays Peak is the highest point on the Continental Divide of North America.
  4. ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 The elevation of this summit has been converted from the National Geodetic Vertical Datum of 1929 (NGVD 29) to the North American Vertical Datum of 1988 (NAVD 88). National Geodetic Survey

Further reading

  • Fishman, N.S. et al. (2005). Principal areas of oil, natural gas, and coal production in the northern part of the Front Range, Colorado [Geologic Investigations Series I-2750-B]. Reston, VA: U.S. Department of the Interior, U.S. Geological Survey.
  • Sprague, L.A., R.E. Zuellig, and J.A. Dupree. (2006). Effects of urban development on stream ecosystems along the Front Range of the Rocky Mountains, Colorado and Wyoming [USGS Fact Sheet 2006-3083]. Reston, VA: U.S. Department of the Interior, U.S. Geological Survey.

External links

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