The Greene County Sheriff's Office is asking for help in identifying a man who was found unresponsive in a southwest Missouri field and later died.

The Springfield News-Leader reports deputies were called Sunday morning to check on a man in a field near Halltown. Emergency responders performed CPR but the man was pronounced dead in a hospital emergency room.

The Sheriff's Office says there were no signs of physical trauma or foul play, and that an autopsy is scheduled for Tuesday.

The man is described as being white, in his late 30s or 40s and about 6 feet tall. He weighs 175 to 190 pounds and has brown hair and brown eyes.

Investigators say the man was carrying a lighter, a pack of Cheyenne cigarettes and a pocket knife.