Stather, a 41-year-old pulmonary specialist from Calgary, died Friday while making a BASE jump in a wing suit in Coconino County, the Canadian Broadcasting Corp. reported Monday.
Stather had told two companions he was going to make one more jump and climbed back up a cliff, Detective Pat Barr of the county sheriff's office said.
"The two stayed behind at the bottom to watch for him," Barr said. "After a period of time went by and they did not see him jump, so they decided to hike back to the top. They could not locate him at the top of the rim where their cars were parked."
Stather's body was found the next day.
Police said he had jumped from a steep cliff.
"Between where they would launch from and the canyon floor, there is terrain on the way down, almost as if it's a ridges and a step type terrain," Barr said.
"The idea is to fly over all those ridges to get down to the bottom, and it appears he may have miscalculated the height of one of those ledges and did collide with it."
BASE stands for building, antenna, span and earth. BASE jumpers make their leaps without aid of aircraft.
Elaine Dumoulin, a colleague and friend of Stather, said he was a frequent skydiver.
"He was an amazing guy. He was very generous, very intense. He was living his life 200 percent," Dumoulin said.
"One thing he taught me was actually to live every day as if it was the last one and to enjoy every moment because he said life was short, but we needed to live it intensely, and he was passionate about everything he was doing."