The truck was discovered after police received a phone call around 3 a.m. reporting the sound of a collision on the 400 block of Roberts Road, and another reporting that a hydrant had been knocked over in the same area, police said.
Officers found an unoccupied white GMC truck 70 yards down the hillside next to the road. The truck appears to have been traveling north on Roberts Road when it veered to the left, driving over the sidewalk and striking the hydrant before rolling down the hill and landing upright, police said.
When police contacted the vehicle's owner by phone, he refused to meet with them in person and told officers that the truck had been taken by someone else at the Linda Mar Shopping Center.
The investigation is ongoing, police said.