"I was walking towards the bridge along the shore when I saw something in the water," she told County 10. "I had to take a second look and I realized it was a body."
She said the body was of an average-size male, wearing a black shirt and black pants.
She said she called 911 and detectives arrived.
The Fremont County Sheriff's Office didn't immediately respond to a request for comment. However, in a statement posted by KCWY News 13 to its Facebook page, the office confirmed that a body had been found by someone walking in the area at 8:40 a.m.
The statement added: "The death appears to be accidental in nature and possibly that of a drowning. There is no evidence at this time that would indicate foul play."
The sheriff's office added that the body had been in three feet of water and that evidence suggested the man went into the water at that very part of the Big Wind River. The man has yet to be identified.