SILVER CITY, Idaho -- The Bureau of Land Management has closed off an abandoned mine after a mineshaft abruptly collapsed, opening a large sinkhole about 50 miles southwest of Boise.

The sinkhole, which appeared in the historic mining town of Silver City near the community park and a popular campground, was deemed an "immediate safety risk" by the BLM.

Officials say the hole - discovered on Thanksgiving weekend - was about 15 feet wide and 25 feet deep.

The BLM said the hole was filled with a combination of boulders and gravel on December 7. Inspectors will return to the site in the spring to ensure the fill remains stable.

The BLM credited winter residents Bobby and Kathie Owens with first reporting the mineshaft collapse, allowing the agency to move quickly to close off the area and protect the public. Crews worked closely with the Silver City Homeowners Association to make sure everyone stayed safe during the closure work.

“We notified the BLM about the issue and their response was great,” Jim Hawe, Chairman of the Silver City Homeowners Association, said in a release. “We really appreciate the effort they made. It couldn’t have gone any better.”

The BLM cautioned that the public should keep their distance from all abandoned mines - not just those that have fallen in. Unused mines frequently contain dangers including unused explosives, drop-offs and high levels of carbon dioxide.

“With tens of thousands of abandoned mine lands throughout the west, we really want people to understand how dangerous they can be,” BLM Abandoned Mine Lands Specialist Carrie Wontorcik said in a release. “When it comes to abandoned mines, we tell everybody to stay out, stay alive.”

The public is asked to report any abandoned mines they come across to the local BLM or Forest Service office.