One hiker is dead and his friend hospitalized after they ran out of water on an unmarked trail in South Dakotas Badlands National Park.

Maxwell Right, a 22-year-old from Missouri, died on Wednesday from suspected dehydration and exposure, the Pennington County Sheriffs office wrote in a news release on Facebook . His hiking companion, whose name has not been released, is a 21-year-old who was flown to a hospital.

Though the sheriffs office initially said the two men headed out on the unmarked trail because of a social media challenge, Rights sister, Lucille Right, told them that they had actually been following a trail on a hiking app.