On September 10, 1993, at 1545 eastern daylight time, a Cessna 177RG, N2074Q, encountered severe turbulence 13 miles southeast of Valdosta, Georgia. The personal flight operated under 14 CFR Part 91 with no flight plan filed. Visual weather conditions prevailed at the time of the accident. The airplane was substantially damaged; the pilot was not injured. The flight departed Hampton, Georgia, at 1345 hours. According to the pilot, while cruising at 7500 feet, a cloud layer was encountered which forced him to maneuver the airplane to maintain cloud clearance. As the airplane descended to 6000 feet, it encountered turbulence which resulted in a loss of 4000 additional feet. Simultaneously, the landing gear extended partially, the wing flaps extended, and the alternator showed a discharge. After regaining control of the airplane, the pilot elected to return to Hampton. During the return flight, he discovered that the landing gear would not extend; a gear up landing was completed at Hampton. Examination of the airplane confirmed symmetrical deformation to both inboard wing panels and other airframe deformation. The airplane sustained minor damage during the gear up landing. The pilot received a preflight weather briefing. A review of the sequence weather reports near the accident revealed a broken cloud layer at 5000 feet and an overcast layer at 15,000 feet. Moody Air Force Base, 20 miles northeast of Valdosta, reported broken cloud layers at 3500 and 4000 feet, and an overcast layer at 25,000 feet. Visual weather conditions were reported below 2800 feet. The pilot reported encountering the turbulent conditions as he flew within a mile of a cloud buildup which he believed to have been a thunderstorm.