Witnesses told Houston police that Pelton's horse fell into some deep water and panicked.
That's when authorities say Pelton either fell or was bucked off the horse.
They said it looked like his foot got caught in the stirrup, and then he went underwater and may have hit his head.
Pelton's horse made it back across the water, but the rider did not.
Crews searched for six hours. His body was recovered shortly before 10pm Saturday.