Front Range

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Front Range
Peaktopeak.JPG
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
Image Wpdms nasa topo front range.jpg
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[edit]

Sandstone slabs along the eastern edge of the front range

Pikes Peak Granite[edit]

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[edit]

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[edit]

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[edit]

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[edit]

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[edit]

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[edit]

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[edit]

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[edit]

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[edit]

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[edit]

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.

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

Travel through the Front Range[edit]

The main interstates that run through the Front Range are Interstate 70, which crosses west of Denver, Colorado, and Interstate 80, which crosses near Laramie, Wyoming. U.S. Route 34 travels through the mountains near Loveland, Colorado. Along with roads that run through the Front Range, the Union Pacific Railroad operates two rail lines through the mountains, one, the Overland Route, which goes southern Wyoming, which runs parallel to I-80 for much of the way, and the other which is former Denver & Rio Grande Western Railroad trackage, which runs parallel to the Colorado River and through the six and a half mile long Moffat Tunnel. The latter route, along with being a freight line, is also used by Amtrak's California Zephyr.

See also[edit]

References[edit]

  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. ^ a b c d e f g h i j k l m 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. ^ a b c d e f g h i j 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[edit]

  • 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[edit]