The last text message a Minnesota man sent to his wife during a hike he never came back alive from revealed that he 'was more exhausted than expected'.

Grant Gardner, who went missing in late July while hiking Wyoming's Bighorn Mountains, was found dead on August 26 near the top of Cloud Peak, the highest summit in Wyoming's Bighorn Mountains.

The experienced, 38-year-old hiker had set off on a three day trek through the area that was supposed to end with him reaching the 13,171-foot peak.

He made contact with his wife, Lauren Gardner, on the evening of July 29, letting her know he'd made it to the summit. That was when he told her he 'was more exhausted than expected'.

He failed to return home and a sprawling search operation began after his vehicle was found still parked near the West Ten Sleep trailhead.