Custer, SD – Custer County Sheriff’s Office reported that units initially responded to a small wildland fire burning within the forest on Monday, June 6th. While working to contain the flames, responders discovered the unexploded homemade explosive device.

Officials said the presence of the device not only endangered the first responders on the scene but also actively delayed suppression efforts while teams worked to mitigate the threat.

Upon further inspection, technicians determined the device appeared to be a type of homemade tannerite. The explosive was subsequently moved to a secure area and made safe through a controlled detonation.

Authorities used the incident to remind the public that exploding targets are illegal in the Black Hills Fire Protection District, carrying the same restrictions as campfires and fireworks.

“Despite being green, it’s very dry,” the Custer County Sheriff’s Office said in a statement. “Please follow the law.”

The investigation into the origin of the device remains ongoing near Rapid City.