On August 10, 2002, about 2116 eastern daylight time, a Cessna 500 (Citation), N688CF, was substantially damaged during a deer-strike, while departing from Griffing Sandusky Airport (SKY), Sandusky, Ohio. The certificated commercial pilot and passenger were not injured. Night visual meteorological conditions prevailed for the planned flight to Ashland-Boyd County Airport (DWU), Ashland, Kentucky. An instrument flight rules flight plan was filed for the business flight conducted under 14 CFR Part 91. The pilot reported that he was departing on runway 09, a 3,559-foot long, 60-foot wide, asphalt runway. During rotation, a deer crossed the runway and impacted the nose gear of the airplane. The pilot continued the takeoff and diverted to Toledo Express Airport (TOL), Toledo, Ohio. He then made two passes over TOL, while ground rescue personnel verified that the nose gear was not fully extended. After burning additional fuel, the pilot made an approach to runway 25 at TOL. About 100 feet above the ground, he shut down the engines, fuel shut-off, and generators. The airplane then landed on runway 25, and came to rest on the fork of the nose gear and gear doors. The reported weather at an airport approximately 20 miles east of the accident site, at 2053, was: wind from 050 degrees at 5 knots; visibility 10 miles; clear skies; temperature 66 degrees F, dew point 50 degrees F; altimeter 30.14 inches Hg. According to a Federal Aviation Administration (FAA) inspector, and a representative from the airplane manufacturer, the airplane sustained substantial damage to the bottom fuselage, forward pressure bulkhead, and nose gear. Review of an FAA Airport/Facility Directory revealed, "Deer on an invof arpt...," with respect to SKY information. Additionally, the airport manager of SKY stated that the airport does not have a perimeter fence. He added that the airport was privately owned, and received little funding. The manager further stated that he could only recall one other deer-strike in the past 10 years. Review of the Safety Board's database, from January 1988 to January 2003, did not reveal any additional deer-strike incidents or accidents.