The private pilot reported that shortly after takeoff from runway 35, "the plane settled and would not climb. I believe we were in a downdraft. Thinking we could not clear rising terrain ahead, I turned into the wind." The pilot stated that after turning into the wind the airplane climbed better, but he still felt as if the airplane was in a downdraft. After maneuvering the airplane, the pilot acknowledged that the airplane was going to contact the ground and pulled the yoke full aft "to land uphill." The airplane contacted the ground, encountered heavy brush, and nosed-over resulting in substantial damage. The pilot did not report any pre-accident mechanical anomalies. At the time of the accident the airplane contained approximately 27 gallons of fuel (100LL). The pilot reported that the airplane's gross weight at takeoff was 1,989 pounds. He reported that the airplane's maximum gross takeoff weight was 2,000 pounds. The pilot reported that the winds were from 320 degrees magnetic at 10 knots, gusting to 15 knots. He reported a temperature of 50 degrees F. The published airport elevation for Chiloquin State is 4,217 feet above mean sea level (msl).