On November 20, 1999, at 2100 mountain standard time, a Cessna 210D, N3928Y, was substantially damaged during landing at Sheridan County Airport, Sheridan, Wyoming. The private pilot, the sole occupant in the airplane, was not injured. The airplane was being operated by the pilot under Title 14 CFR Part 91. Visual meteorological conditions prevailed for the local flight which originated approximately 35 minutes before the accident. No flight plan had been filed. The pilot said that this was the first flight after the annual inspection. He was flying from Billings, Montana, to Sheridan, Wyoming, and had put the leading gear handle down for landing. He didn't get a positive gear lock light, so he cycled the landing gear several times in an attempt to get a positive gear down and locked indication. He then attempted to hand pump the gear down, but still had no positive down and locked light. He landed the airplane, and during the landing roll the right main landing gear collapsed. Subsequently, the right horizontal stabilizer and the right wing tip were bent when they struck the ground. Postaccident examination of the engine driven hydraulic pump pressure revealed that its output was 200 pounds per square inch (psi). The maintenance personnel that worked on the airplane said that normal pump pressure output should be 2,725 psi. The hydraulic pump was replaced, and the landing gear cycled normally.