Principal Investigator:		John A. Bissonette USGS Biological Resources Division, Utah Cooperative Research Unit Department of Fisheries and Wildlife, Utah State University
Graduate Research Assistant:		Mary L. Harrison Department of Fisheries and Wildlife, Utah State University M.S. Wildlife Ecology (in progress)

Numerous approaches have been used to reduce deer mortality along roadways and allow for safe passage of deer across the roadway. The most common technique is a combination of deer fencing and underpasses. Recent studies have suggested that at-grade big game crosswalks are effective at reducing deer-highway mortality (Lehnert, 1996). However, at-grade crossings, and fencing that is not rigorously maintained allow deer access to the highway right-of-way (ROW) where they are vulnerable to vehicle collisions. One-way steel gates are usually installed in conjunction with deer fencing in many areas. Evaluation of their effectiveness has had mixed results. Reed et al. (1974) found that gates were relatively effective in allowing deer to escape the ROW. Lehnert (1996) found that only 16.5% of deer that approached the gates used them to escape the ROW. Another technique that has been employed to help trapped deer escape the ROW is the use of earthen return ramps. Earthen return ramps are mounds of dirt constructed against the ROW fence in a design that allows deer a one-way exit from the ROW but prevents access to the ROW from the ramps.

The primary goal of this study is to determine the relative effectiveness of earthen ramps vs. one-way gates in allowing deer to exit the ROW and thus in reducing highway mortality. Nine earthen ramps have been installed along U.S. 89 in Sardine Canyon between Brigham City and Logan. Eight ramps have been installed along U.S. 40 near the Jordanelle Reservoir by Park City, Utah. During the summer of 1998, track beds were established on all nine ramps in Sardine Canyon and three of the ramps in the Jordanelle area. For comparison, track beds were also established at 10 one-way gates in Sardine Canyon and four one-way gates along U.S. 40. During 1999, remote sensors will be used to record deer passage on the ramps.

Preliminary results clearly indicate that deer prefer to exit the ROW via earthen return ramps. Using standardized index values we found that earthen ramps are about 10 times more effective in allowing deer to escape the ROW than one-way gates. The use of earthen ramps may have widespread benefit along areas of deer-fenced highways that still experience fairly high deer mortality. Analysis of deer mortality along other game-fenced highways in Utah is currently being conducted. Placement of ramps along these roadways may help to alleviate deer mortality in these areas as well.