A 21-year-old Riverton resident faces criminal mischief and trespass charges after his car sparked a fire that charred a rock art preserve on the west shore of Utah Lake.

Authorities say Dominic Deros drove off State Road 68 to evade a road closure associated with Saratoga Springs’ Knolls Fire in late June.

That maneuver started a second blaze that scarred 388 acres, including parts of the Adelbert Doyle Smith Family Archaeological Preserve, and disrupted crews’ efforts to fight the Knolls Fire that was threatening subdivisions along Saratoga Springs’ southern periphery.

Utah County Sheriff’s Sgt. Spencer Cannon said Monday that both class B misdemeanor charges were in justice court. He said that Deros cut a fence near the highway’s mile marker 17 to enter private property.

“Most of the time, when someone gets charged in a case related to a fire, it’s not for causing the fire itself,” Cannon said. “On the criminal side, it’s for either trespassing or violating some rule.”

Investigators believe Deros drove off the closed State Road 68 on the evening of June 28, not long after the Knolls Fire erupted. He allegedly drove onto private land between the highway and the lake, forming the basis for the trespassing charge.

The vehicle then passed through an unsecured gate and onto the rock art preserve, according to preserve manager Randy Griffin. Heat from the vehicle ignited dry brush in a ravine inside the 197-acre preserve.

The so-called Mile Marker 17 Fire quickly spread and burned the vehicle. A female passenger suffered severe burns and was flown to the University of Utah’s Burn Center for treatment, according to Cannon.

High winds pushed the flames toward a home south of the preserve, but crews were able to cut lines that stopped the fire’s progress.

The blaze destroyed fencing and seared vegetation on at least half of the privately owned preserve, which will be closed to the public indefinitely, Griffin said.

All told, 218 acres of private, 135 acres of federal and 37 acres of state trust land were burned in the Mile Marker 17 Fire, according to the Bureau of Land Management.

— Tribune reporter Brian Maffly contributed to this article.