The pilot reported that, he planned an off-airport landing on a dirt road. He performed a series of passes to confirm the road condition and decided to proceed with the landing. During the rollout, the dirt road elevation lowered with respect to the berms on either side, and the wings contacted vegetation, which damaged the left wing. The pilot and his passenger exited the airplane to inspect the damage and determined that the airplane was airworthy and able to fly to a nearby airport with only the pilot onboard. The pilot stated that for the accident takeoff, near rotation speed, the left main wheel dropped into a rut of soft sand, the airplane veered left, the left wing contacted a berm, and the airplane spun around and came to rest inverted. Substantial damage was sustained to the wings and fuselage. Witnesses reported that they saw the airplane climb before veering left and descending back to the ground. The pilot reported no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.