Investigators believe drugs or alcohol were a factor in two single-vehicle crashes that injured four people Sunday near Deer Park.

The first crash occurred about 3 p.m. on U.S. Highway 395. A Jeep SUV traveling south “left the road to the right, overcorrected across the northbound lane and left the roadway, striking a tree,” according to a Washington State Patrol report.

Troopers believe the driver, Randy S. Sandven, 30, of Spokane, was under the influence, according to the report. He and his passenger, Galadriel K. Strickland, 30, of Deer Park, were taken to Providence Sacred Heart Medical Center. Neither had been wearing a seatbelt.

Strickland was in critical condition Monday morning, and Sandven had been released, a hospital spokeswoman said. Charges are pending, WSP said.

The second crash took place about 8 p.m. farther north on state Highway 231. Dean L. Rice, 58, of Addy, Washington, faces a vehicular assault charge for allegedly crashing a motorcycle into a deer while under the influence.

The WSP said Dean was injured but not hospitalized. His passenger, Athena L. Mace, 36, of Valley, Washington, was thrown from the bike and airlifted to Sacred Heart. She was listed in satisfactory condition Monday morning.