Front Range, a range of the Rocky Mountains in central Colorado. It extends for about 175 miles (280 km) from the Arkansas River to the Wyoming border and is the easternmost range of the Rockies, rising abruptly from the Great Plains just west of Denver. Grays Peak, at 14,270 feet (4,349 m), is the highest summit in the range. Only slightly lower are Mount Evans, Longs Peak, and Pikes Peak.