On July 29, 2003, at 1100 central daylight time, a Beech M35 (Bonanza), N9785R, piloted by a private pilot, was substantially damaged during landing rollout at the Wittman Regional Airport (OSH), Oshkosh, Wisconsin. The aircraft touched down in the grass area adjacent to runway 27 (6,178 feet x 150 feet, asphalt). Visual meteorological conditions prevailed at the time of the accident. The flight was being conducted under 14 CFR Part 91 and was not on a flight plan. The pilot and passenger reported no injuries. The flight originated from the Mason City Memorial Airport (MCW), Mason City, Iowa, at 0930. Special flight procedures are in effect at OSH during the Experimental Aircraft Association (EAA) AirVenture convention. The arrival procedure in use specified for aircraft to approach the airport from Fisk intersection, located approximately 6 miles southwest of OSH. Downwind for runway 27 is entered by referencing a gravel pit north of the runway 9 threshold. Two alternate landing points, in addition to the normal runway threshold, were established on runway 27 and marked with orange and green dots. The Notice to Airmen (NOTAM) denoting the special flight procedures for OSH states, 'On Runway 27 Oshkosh Tower controllers may request that you land on one of the colored circles ("dots"). The "orange dot" is 1,500 [feet] from the Runway 27 threshold (4,678 [feet] remain); the "green dot" is 3,000 [feet] from the Runway 27 threshold (3,178 [feet] remain).' The NOTAM also states that a waiver allowing reduced arrival and departure standards for category 1 and 2 aircraft was issued for OSH operations during EAA AirVenture. In his written statement, the pilot reported he entered downwind for runway 27 and the control tower cleared him to land on the green dot. The pilot stated: "About mid-point on base an aircraft came past the green dot moving slowly (probably on rollout from landing at [runway] 27 threshold). I extended base to gain time and space. Got too low for the tight turn to [the runway] (might have dragged the right wingtip) and landed on [the] grass on south side of [the runway]". The pilot reported he turned back toward the runway, but subsequently skidded across the runway and came to rest in the grass on the opposite side. He noted the nose wheel steering may have been damaged as the aircraft entered the pavement because he was not able to steer properly once the aircraft was back on the runway. The left flap may have hit a runway light along the south side of the runway and, as the aircraft departed the north side of the runway, it impacted an airport sign, according to the pilot. The pilot noted he made a "good landing" in the grass adjacent to the runway and feels he should have stayed on the grass for the rollout. He also noted he was unsure of the proper go-around procedure due to the density of traffic in the pattern at the time. The NOTAM did not contain any guidance in the event of a go-around. The pilot reported no malfunctions with the aircraft prior to the accident. The post-accident examination revealed damage to the left flap, the right wing immediately forward of the main landing gear, and the nose wheel tire. The nose wheel steering linkage was intact and appeared to be undamaged.