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During times of no precipitation during the spring, powdered limestone (23 Kg bags of CaCO3) was placed along all overpasses to help in tracking animal passage. RESULTS Twenty track count transects were conducted from 1988 - 1991. Figures 1 and 2 present track count data for elk (Cervus elaphus), mule deer (Odocoileus hemionus), and pronghorn antelope (Antilocapra americans). A total of 22.9 percent of all elk tracks were found on overpass structures (Table 1). Mule deer used the overpass structures 12.1 percent of the time and antelope - 3.3 percent. Underpass usage data (Table 2) showed elk using this type of structure most of the time - 45.2 percent. Mule deer crossed underpass structures during 23.8 percent of their passage and antelope used them 48.5 percent of their crossing. Passage beneath the beltline structure (Table 3) that has a 0.9 meter maximum clearance occured as follows: Elk passed under the beltline a total of 31.8 percent of the time, mule deer passage totaled the most for this species - 64.1 percent. Antelope crossed under the belt a total of 49.5 percent which was slightly more than their underpass usage of 48.5 percent. Antelope, therefore were for the most part, evenly distributed when it came to using underpasses or passing beneath the beltline structure. No large elk bulls or large mule deer bucks were counted passing under the beltline structure during the entire study. In fact track count observations showed mature males of both species avoided crossing under the belt due to antler clearance problems. These large males would follow the beltline to the next available crossing. The Colorado Division of Wildlife conducted field census studies on big game management areas within Rio Blanco County, Colorado (Del Piccolo 1991). Elk bull / cow sex ratios over the last 2 years (1989-1990) averaged 30 bulls per 100 cows. Mule deer buck / doe sex ratios averaged 6.5 bucks per doe for 1989-1990. Therefore, crossings other than under the 0.8 meter beltline were crucial for large antlered bulls and bucks. Pronghorn antelope horns do not get large enough to prevent males from crossing under the belt. On one occasion during the spring of 1991, a male pronghorn with a average horn length was observed by the author to pass directly under the active beltline with hesitation. Crossing availability for big game and other wildlife along the entire conveyor route is summarized, in Table 4. 75.4$ of the entire conveyor was elevated to an average of 0.8 meters for passage of animals. There was a total of 18$ crossing availability as underpass structures. 2.6 ~ of the beltline was available as overpass structures and 3.3~ of