Text Box: Middle Rocky Mountains Introduction | Mountains | Big Horn Basin | Yellowstone National Park | Yellowstone Continued | Grand Teton and National Monuments | Resources
The Middle Rocky Mountains province, or Middle Rockies, covers a portion of five states, with most of its area in western Wyoming and northeastern Utah, and only a very small part in northwestern Colorado.  The province is in contact with six other geomorphic provinces:  the Great Plains and Wyoming Basin to the east, Colorado Plateaus on the south, and the Basin and Range, Columbia Plateaus, and Northern Rockies on the western side.  Because of the intervening Wyoming Basin, the Middle Rockies province does not touch the Southern Rockies; there are separations  of about 50 miles between the two provinces at  the northeastern and southeastern corners of the Middle Rockies.
General Characteristics
The Middle Rocky Mountains province has a great deal of geological diversity, possessing characteristics that are common to all surrounding provinces.  For example, the Big Horn Basin is similar in geology and topography to the Great Plains to the east; the Wasatch Mountains and the Teton Range have a structure very much like the fault blocks of the Basin and Range province to the west; and Yellowstone Plateau is closely related to the volcanics of the Columbia Plateaus.  Also, although the Middle and Southern Rockies do not touch, there are some similarities among the two provinces because the rock types and basic structures of the two provinces are connected beneath the sediments of the intervening Wyoming Basin. 
Although there are very rugged mountains in the Middle Rockies, elevations are generally less than in the Southern Rockies, but higher on average than those in the Northern Rockies.  Altitudes in the province are generally between 5,000 and 12,000 feet, although there are many peaks that exceed 12,000 feet in elevation and some that are higher than 13,000 feet in several ranges, including Gannett Peak (13,804 feet) in the Wind River Range, the tallest peak in Wyoming and the province.  In general, the Middle Rockies did not present as many major obstacles to westward travelers as the Southern Rockies; the relatively flat-floored basins between several of the ranges, several significant canyons and river valleys through the mountains, and generally lower elevations made it easier to traverse these ranges than those to the south. 
The Continental Divide extends a relatively short distance through the province, in a southeast-northwest direction, including along the crest of the Wind River Range, through Yellowstone National Park, and extending into the Northern Rockies province near the northwestern corner of Wyoming.  Approximately half the drainage of the province is toward the west (the Pacific Ocean) and half toward the Atlantic Ocean or Gulf of Mexico.  Several major rivers arise within the province, including the Snake, Green, and Yellowstone rivers.  The Snake River begins in the southern portion of Yellowstone National Park, flowing southward through Grand Teton National Park including Jackson Lake until turning toward the west to cross the Columbia Plateaus province and join the Columbia River in southern Washington.  The Green River also rises west of the Continental Divide, near Gannett Peak at the northwestern end of the Wind River Range in the Green River Lakes, and eventually flows into the Colorado River in southeastern Utah.  The Yellowstone River begins east of the Continental Divide slightly southeast of Yellowstone National Park and flows first northwestward and northward, and then turns eastward onto the Great Plains, finally emptying into the Missouri River in western North Dakota. 
 Middle Rocky Mountains Introduction | Mountains | Big Horn Basin | Yellowstone National Park | Yellowstone Continued | Grand Teton and National Monuments | Resources