The pilot reported that, while landing uphill, on an unimproved gravel airstrip, the tailwheel-equipped airplane landed "smooth." He added that, while taxing to the crest of the hill, a gust of wind forced the airplane to become airborne. The airplane then drifted to the left and he attempted to correct with full right aileron and maximum power. The airplane continued to bank left until "the wind forced the tail in a counter clockwise motion", which resulted in the airplane landing on the right main landing gear. Subsequently, the right main landing gear collapsed; and the right wing and right horizontal stabilizer struck the ground. The airplane sustained substantial damage to the right wing lift strut and the right horizontal stabilizer and elevator. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. The pilot reported the weather at the time of the accident to be, wind from 360° at 20 knots, gusting to 25 knots. The pilot landed on about a 360° heading.