On March 16, 1997, about 1855 Alaska standard time, a ski equipped Cessna 170B airplane, N3486C, sustained substantial damage during an attempted takeoff from an off airport site near Newman Creek, located approximately 60 miles south of Fairbanks, Alaska. The solo private pilot was not injured. The 14 CFR part 91 flight operated in visual meteorological conditions. A VFR flight plan was in effect. The airplane last departed Lakloey, Alaska, about 1645, and was returning to Lakloey at the time of the accident. The pilot reported the accident occurred during his seventh departure from the same, unimproved "bush" strip that same day. On the accident takeoff attempt, the pilot said he was unable to maintain directional control, and the airplane departed the takeoff area and entered an area of trees and brush. The left wing contacted a tree, and the airplane turned abruptly to the left, into more brush. The airplane received damage to about five feet of the outboard section of the left wing, the left wing rear spar is broken in the vicinity of the fuel tank, the fuselage near the left wing attach point is wrinkled, and the right aileron and elevator are damaged.