JACKSON, Wyo. (AP) — Wildlife refuge officials say a man with a drone caused 1,500 elk to stampede half a mile through the snow.

The stampede happened Monday at the National Elk Refuge in western Wyoming. Elk and bison often congregate at the refuge to eat feed put out to help them survive the winter.

This winter has been especially harsh for wildlife. More than 3 feet of snow has piled up, conditions that can be stressful for all kinds of animals.

Federal officials say they gave 45-year-old David A. Smart of Washington, D.C., a $280 ticket after he launched the drone from a highway pullout and flew it over the resting elk herd.

Disturbing wildlife is punishable by a fine up to $5,000.