Reducing coyote (Canis latrans) predation can be an important management objective. Here, we evaluated the efficacy of electronet fencing for excluding coyotes from focal areas on black tailed prairie dog (Cynomys ludovicianus) colonies, measured the effect of fencing on wild-born black-footed ferret (Mustela nigripes) kit survival, and modeled costs and benefits of fencing. From 27 July to 2 October 2010 in north-central Montana, USA, we erected and maintained 7.7 km of electronet that enclosed 108 ha on portions of 2 prairie dog colonies. We monitored 2 female ferrets and 6 kits inside exclosures and 3 females and 12 kits outside of exclosures. Percent of coyote sightings in the protected areas was 6 times less than expected during the exclosure period (42% pre-exclosure, 7% exclosure, 47% post-exclosure). We conclude that the electronet fencing was effective for dramatically decreasing coyote activity in focal areas where black-footed ferret litters were being raised. We found evidence that survival of kits living primarily in protected areas was 22% higher, but we qualify this finding because of low sample sizes and because our monitoring activity on the study site may have influenced coyote activity. We estimated one-time costs for fencing to be US$4,464/km and operation and/or maintenance costs for the 68 days of fence operation to be US$641/km. If fencing increased survival by 20–30%, then total cost per ferret kit not lost to coyote predation would range between US$5,400 and $3,600, or US$2,550 and $1,700 if fence set-up–take-down labor and use of an all-terrain vehicle were donated. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.