The Laramie Basin - Mountains and Plains: The Ecology of Wyoming Landscapes - page 288

Fig. 17.5. topographic features in the Laramie Basin west of
Laramie, with Sheep Mountain in the background. Highways
and the Big and Little Laramie rivers are shown. note the
location of the Airport and Harmony benches, and the large
deflation basin known as Big Hollow, west of the Airport
Bench. Bamforth Lake is in a smaller deflation basin. Lake

Hattie was enlarged to store more water for the irrigation of
hayland in the Pahlow strath, a term used for the valley be-
tween the south rim of Big Hollow and the Harmony Bench.
Drawing by Brainerd Mears, Jr., courtesy of the Wyoming
Geological Survey, Laramie.

over much of the area (see chapter 2). Such rocks have
been eroded from the Laramie Basin because of its high
elevation.

annual temperature from 1991 to 2010 at the Laramie
Regional Airport was 41°F, with July average highs and
lows of 80°F and 49°F, respectively (fig. 17.6). 16 Annu-
ally, most of the basin had only 75-100 frost-free days
during this time. the short growing season combined
with relatively cool summer temperatures limits tillage
agriculture to mostly hay production where irrigation
water is available, such as near the Big and Little Lara-
mie rivers and along Rock creek just to the north of
the basin.

Elevation, Climate, and a Double Rainshadow

With an average elevation of about 7,200 feet, the
Laramie Basin has the coolest climate of all the basins
in Wyoming, though similar to the Washakie and
Green River basins to the west (see fig. 3.7). the mean