Collisions between large vertebrates and vehicles along roadways are an increasing concern, not only because of ecological consequences, but also because of associated economic and social costs. We used a large-scale, long-term data set comprising several databases from Utah to summarize and analyze these costs. The overall cost for 13,020 collisions from 1996 to 2001 in Utah was approximately $45,175,454, resulting in an estimated average per year cost of about $7,529,242 and a mean collision cost of $3,470. These figures include human fatality costs of $24 million (53% of total costs); vehicle damage costs of $18 million (39%); loss of deer, valued at $2.7 million (6%); and human injury costs of $1 million (2%). Cost-benefit analyses have shown that mitigation efforts, which are prioritized based on road-kill data, can produce positive net economic gains and also increase driver safety.