The pilot reported that during the downhill takeoff from a remote unimproved airstrip, with a quartering headwind, the wind shifted as the airplane became airborne. The airplane settled "with about 100 yds left on the runway" and he continued "trying to milk the flaps" to become airborne while continuing downhill. The airplane never attained flying speed again and settled into a creek bed. After the impact with terrain, the pilot reported there were "several wind gusts of 15-20 mph coming downhill".
The airplane sustained substantial damage to the fuselage.
The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation.