CHEYENNE, Wyo. (AP) — The mother of a man who died on a 2011 backpacking trip to India has dropped her appeal of a judge's decision dismissing her lawsuit against a Wyoming training academy.

Elizabeth Brenner of Minnetonka, Minnesota, had sued the National Outdoor Leadership School based in Lander, Wyoming.

Brenner had claimed NOLS was negligent in the death of her 20-year-old son, Thomas Plotkin. He slipped into a ravine while on a NOLS expedition and his body was never found.

U.S. District Judge Alan B. Johnson of Cheyenne dismissed Brenner's lawsuit last year. Johnson noted Plotkin had signed agreements acknowledging the program involved risks.

Brenner had appealed Johnson's dismissal to a federal appeals court in Denver.

Brenner and NOLS filed a stipulation in the federal appeals court this month ending the appeal.