A small twin-engine plane crashed about 10 miles northwest of the Buffalo Bill Reservoir early Saturday afternoon. The Park County Sheriff's Office said Sunday morning that it does not yet know how many people were aboard, but it appears no one survived. (Updated story available here.)

The plane went down around 12:20 p.m. Saturday in an area along Big Tree Creek, northwest of Logan Mountain and inside the Shoshone National Forest, the sheriff's office said in a news release. The location is about 1.5 miles west of the northern end of Rattlesnake Creek Road and the Mooncrest Ranch, the sheriff's office said.

Air traffic controllers in Salt Lake City saw the plane suddenly drop off their radar and contacted the sheriff's office at 12:35 p.m., the release said.

The Park County Search and Rescue Unit was immediately called into service. A Search and Rescue airplane found the crash site shortly after 3 p.m. and ground teams reached the area not long after that, the release said. They processed the scene until darkness fell.

"Due to the condition of the crash site, the identity of the plane as well as the identity or number of victims could not be confirmed," sheriff's office spokesman Lance Mathess said in the news release.

Members of the Search and Rescue unit were returning to the scene of the crash Sunday morning.