Check out the review of the mitigation measures for bighorn sheep along Hwy 200 near Thompson Falls, Montana. The review has images that illustrate what has been constructed to reduce collisions with bighorn sheep. http://www.marcelhuijserphotography.com/blog/2016/10/road-ecology-blog-mitigation-for-bighorn-sheep-near-thompson-falls-montana-usa
Wildlife fences along highway sections that are at least 3 miles (5 km) long, almost always reduce ungulate-vehicle collisions by at least 80%. If shorter highway sections are fenced, the average effectiveness is reduced to about 50%. Furthermore, the effectiveness for individual road sections varies greatly. This article was published in the journal Biological Conservation and includes practical recommendations. E-mail me to request a PDF of the article.