The mountains consist of a series of
Precambrian Sherman
granite monadnocks rising above a broad
erosion surface that form extensive unwooded parks whose surfaces are generally at about above sea level. The high peaks of the range, which are much lower than those commonly associated with the Rocky Mountains, rise abruptly above the surrounding
peneplain to altitudes between and above sea level, with the exceptions of
Laramie Peak in Wyoming which tops out at and
South Bald Mountain in Colorado rising to . The granitic soils were formed from the erosion of the surrounding monadnocks and have an effective depth of less than . Three principal
life zones are represented in the Laramies: Upper Sonoran, Transition and Canadian. Some early sources indicated that the Hudsonian Zone occurs on Laramie Peak but there is nothing distinctive about either the flora or fauna on the top of this peak, for it consists of nothing but a large granite outcrop. On the eastern and north eastern slopes of the range the prairie/mountain transition is very gentle at the south end (between Cheyenne and Laramie) and much more abrupt and broken farther north. The elevation is lowest, about (1370 m), along the
North Platte River. On the western slopes the total relief is much less, as the floors of the three
intermontane basins that border the Laramies on this side (Shirley, Hanna and Laramie basins) rarely drop below . An extensive high plain and semi-desert extends from the Laramie Mountains south west as far as the Shirley Mountains. The Laramie Basin separates the Laramie Mountains from the
Medicine Bow Mountains to the south and west, and its floor is above except for a few depressions and
blowouts (such as Cooper Lake). The Laramie Mountains are bisected by the
Laramie River, which cuts a canyon through the mountains roughly due west of
Wheatland, and then continues its generally eastward course to join the North Platte River near the town of
Fort Laramie. The division marks the southern end of the continuous coniferous forest in the range, and separates the range into two parts. The southern part is generally drier and much more open, with little or no forest except for the southern end at Pole Mountain and surrounding area, where the interesting granite outcrops at
Vedauwoo provide climbing practice and grand picnic scenery. The range is prominently visible from
Interstate 25 between Casper and Cheyenne.
Interstate 80 and the
Union Pacific Railroad cross the range between Cheyenne and Laramie on an outlying ramp of the High Plains called the "Gangplank". ==See also==