Judge Hands Down Prison Time For Would-be Oilfield Bomber

An Upton man will serve 30 months in federal prison after admitting he placed a potentially explosive device at an oilfield site near town last year.

On Jan. 27, U.S. District Court Judge Alan B. Johnson sentenced 40-year-old David Riggle to 30 months’ imprisonment, followed by two years of supervised release, for possessing a destructive device. The court also ordered Riggle to pay a $300 fine.

Riggle was arrested in April 2025 in connection with an incident that began on Nov. 30, 2024, when workers at a drilling company’s storage yard in Weston County smelled propane coming from inside a storage trailer. A routine check revealed a battery-powered device rigged with wires, a timer, and a fuse placed next to an open 100-pound propane tank. Investigators believe the timer was meant to delay ignition so the person who set it could leave the area before it activated. Although the device never ignited, federal authorities said it was capable of serious damage.

The investigation quickly pivoted after law enforcement discovered footprints at the scene leading toward Riggle’s home, about two-thirds of a mile away. A federal search warrant executed at his residence on Dec. 11, 2024, turned up items investigators said were consistent with the components used in the device — including a 6-volt battery matching the one connected to the propane setup, a safety fuse, wires, and soldering tools.

Riggle waived indictment and pleaded guilty on Nov. 12, 2025, avoiding a more lengthy federal indictment process.

In a statement, U.S. Attorney Darin Smith stressed that the case was about more than just an unexploded device: it was about risk. He noted that while the device failed to detonate, it had the capacity to cause “serious injury or death” and led to work disruptions and fear among employees, shaking the sense of community safety in Upton.

The case was investigated by a coalition of state and federal law enforcement agencies, including the Weston County Sheriff’s Office, the Campbell County Sheriff’s Office, the Wyoming Highway Patrol, and the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF). Assistant U.S. Attorney Paige Hammer prosecuted the federal case.