Kofa Queen Canyon, 2006
Bighorn sheep tend to use the highest, most rugged areas within their home ranges for lambing. A summary (Eustis1962) of five years of observations on the Kofa, found that 84% of the ewes and 93% of the lambs were seen in the upper third of elevation of the Kofa Mountains during lambing seasons. Signal Peak and Castle Dome Peak are two of the most distinctive features of the refuge and as such are popular destinations for hikers. Both peaks have maps and route information posted on the internet by hikers or hiking groups. Most use of these areas occurs in the cool winter months (November-March), which strongly overlaps the peak lambing season of January-March, when 75% of lambs are born. A study conducted from 1977 to 1984 documented strong reactions (immediate running, left area and did not return) from Kofa sheep in response to one or two people arriving in the area. Refuge registers on top of the mountains document group sizes as large as 18 on Castle Dome (January 2001) and 11 on Signal Peak (February 2002). Frequent human disturbance of ewes may cause them to abandon these areas for less optimal habitat, which could in turn affect lamb survival.
Researchers at the University of Arizona and United States Geological Survey (USGS) have expressed interest in conducting comprehensive studies documenting the effects of public use on bighorn sheep. Funding for such studies is being pursued.