The California Highway Patrol is investigating a Friday morning accident involving a hay hauler.

The accident occurred shortly after 9:00 a.m. on Highway 78. The big rig hauling hay was reported to be swerving as it went along the roadway and then rolled over on the shoulder of the highway. The driver of the truck sustained injuries to his leg. A portion of the load of hay spilled on the roadway and slowed traffic for a while. The accident remains under investigation.