The trend of most of the ranges in Colorado is north-south, swinging to northwest-southeast near the southern end. Surprisingly, in the northwestern corner of the state there is an east-west trending range, the Uinta Mountains.
Fifty or more mountain ridges in Colorado have been named as separate ranges. Of these, the most prominent, frequently visited ones will be discussed here.
Front Range
The easternmost range of the Rocky Mountains is the longest continuous uplift in the state. It is a relatively simple faulted [anticline] extending from Canon City northward to the Wyoming border, where it splits into two ridges, the Medicine Bow Mountains and the Laramie Range.
Longs Peak challenges technical climbers with its 2000-foot vertical east face, the Diamond. This magnificent cliff is the result of glacial action and freezing and thawing in homogeneous but fractured [granite]. The small remnant of ice and snow at the lower left is all that remains of the [glacier]. The flat summit may be part of an ancient erosion surface formed toward the end of Precambrian time. (Jack Rathbone photo)
Along the highest portion of the range, from Pikes Peak to Rocky Mountain National Park, the Paleozoic and Mesozoic sediments formerly draped over the top of the range have long since been washed away, leaving only the [gneiss], [granite], and [schist] of the mountain core. The almost flat tops of Longs Peak, Mt. Evans, and Pikes Peak, and the rolling upland traversed by Trail Ridge Road in Rocky Mountain National Park are thought to be remnants of the 600-million-year-old erosion surface that once existed at the top of the Precambrian rocks, and that still exists below the [sedimentary rocks] of the Plains Province. This surface, formed near sea level, has been raised 12,000 to 14,000 feet within the Mountain Province.
Throughout most of its length, the Front Range displays some of the most striking high-altitude scenery in the world. Particularly accessible areas, well worthy of visits, are Rocky Mountain National Park, Berthoud and Loveland Passes, Mt. Evans, and Pikes Peak. In these areas the Precambrian rocks can be seen and studied, and the effects of [glaciation] observed.
The [granite], [gneiss], and [schist] of the mountain core are shattered and broken into blocks of various sizes. The breaks between the blocks are called [joints] if there is no apparent displacement between adjacent blocks, and [faults] where there is obvious displacement. The joints frequently appear in parallel arrays or sets; there may be two or more intersecting sets, giving a cross-hatched appearance to large exposures.
