UPDATE (12:09 p.m.): 

Stephanie Frank says two Casper adults and her two children have been found safe near Pinedale and are headed home. 

Their vehicle was stopped by the Sublette County Sheriff's Office, Frank says. 

No other details were immediately available.

Teton County Sheriff's Lt. Matt Carr tells K2 Radio News the family was simply late getting home and had no cell phone service, so they were unable to contact family members in Casper. 

Carr says his office is closing the matter as a resolved case. 

=================================================================

A family member says a pair of Casper residents and two grandchildren are missing after failing to return from a camping trip in western Wyoming.

Susan Frank, 63, and Steve Domonkos, 62, left Casper on Thursday morning. They were supposed to return Sunday afternoon, but daughter Stephanie Frank says she has not heard from them and their phones are turned off.

Stephanie's children, 10-year-old Abigayle and 9-year-old Nicholas, went along on the trip. They also have not been heard from since Thursday.

The group of four was said to be headed to Squaretop Mountain, west of the Wind River Reservation between Pinedale and Dubois.

Stephanie says they were driving a late-model blue Chevrolet pickup truck -- possibly a Silverado -- with Casper license plates. They were towing the camper pictured above.

Stephanie says she called the Teton County Sheriff's Office at about 8 p.m. Sunday. The Teton County Sheriff's Office did not immediately return a phone call seeking comment, and has not confirmed these details as of 9 a.m. Monday.

Stephanie also says someone reported seeing the group in the area of Fish Lake at roughly 7 p.m. Sunday.

Stephanie asks anyone with information on the group's whereabouts to call the Teton County Sheriff's Office at 307-733-2331.

More From KGAB