(CNN) -- A 2-year-old who went missing from his home in Dewey, Arizona, on Monday night was found dead Wednesday, according to the Yavapai County Sheriff's Office.
The body of Emmett Trapp was found by search and rescue personnel at 11:30 a.m. about one mile from his home, lying in a muddy pit once used to collect waste products from a former mining site.
"We are just devastated by the loss of this little boy," sheriff's spokesman Dwight D'Evelyn said.
The area where his body was found on the former Iron King Mine site is being treated as a crime scene, which the sheriff's office described as "common protocol."
The cause of death appears to be a result of spending more than 24 hours exposed to Arizona's elements, Sgt. Jeff Newnum said. An autopsy was scheduled to be performed later Wednesday, he said.
He added that there was "no foul play at Emmett's body that would suggest something was awry."
Emmett was the second 2-year-old boy to go missing from Yavapai County in 10 days.
His case is believed to be unrelated to the disappearance of Sylar Newton -- another 2-year-old who went missing July 25 from a camping site in Rimrock and is presumed dead, D'Evelyn said Tuesday.
Emmett was reported missing by his mother at 8 p.m. Monday, the sheriff's office said in a news release.
The mother told authorities that she and her four children were at their home in the Dewey-Humboldt area, about 80 miles north of Phoenix. When the mother awoke from a nap Monday evening, Emmett -- last seen wearing a pajama top, diaper and no shoes -- was missing.
The family dog had also apparently wandered off with Emmett, but returned when called. The mother told police she searched around the home and immediate area without success.
Newnum said the door to the house was unlocked at the time of Emmett's disappearance, and it appears the boy walked as many four miles, crossing hilly, rough terrain, before he was found.
Newnum credited the muddy terrain in the area with helping find Emmett. He said the small footprints around the site indicate the boy "was by himself."