The Sweetwater County Sheriff's Office will bring in an expert in side-scan sonar from Sublette County's Tip Top Search and Rescue team to look for a boy missing since Thursday evening, it announced in a news release Monday afternoon.

A search by the Sweetwater County's marine unit on Monday had no results.

"We have now canvassed the entire area by air, boat, vehicle and on foot over the last two days," sheriff's spokesman Deputy Jason Mower said.

"Our dive team is resupplying today after two days on the water, and we are meeting early tomorrow morning with everyone involved to coordinate continued search efforts," Mower said.

Mower cautioned against private search groups crowding the area, especially near the cliffs.

"We appreciate everyone's intentions and efforts, but we generally discourage people from taking matters into their own hands," he said. "We would hate for some other accident to occur or someone else to get hurt. We are also bringing in a lot of different people and equipment, so it's important that our team has the room needed to safely operate that equipment."

A 34-year-old Rock Springs man and his 7-year-old son were last seen leaving their campsite in a side-by-side all-terrain vehicle at roughly 11:30 p.m. Thursday.

Witnesses told investigators they never returned to the camp.

About 6:30 p.m. Saturday, searchers found  an oil slick floating on the surface of the water below a 200-foot cliff.

Searchers that afternoon found and recovered a submerged ATV and they also found the body of the man from inside the vehicle.

However, the boy was missing.

The Sweetwater County Sheriff's Office is sensitive to just how tragic this entire situation is for everyone involved, Mower said.

"Our hearts hurt for this family," he said. "We are and will continue to do everything we possibly can to locate this child."

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