, a Cessna 206 with a pilot and cargo, was attempting to take off from the gravel airstrip at Matheson Island. After getting airborne, the pilot did not believe the a/c would climb over trees at the end of the 2,575 foot strip. He turned slightly and attempted to land on the road adjacent to the strip. The a/c skidded out of control and stopped in a ditch beside the road. The pilot was not injured but the a/c is substantially damaged. Two investigators from the TSB are en route to the site. UPDATE TSB reported that the operator stated that the gross weight of the a/c at takeoff was 3,587 pounds and the maximum gross weight is 3,600 pounds. Neither the gross weight of the a/c or the centre of gravity could be verified because the operator had removed the load and fuel before reporting the accident to the TSB. Examination of the a/c and the site revealed no obvious pre-impact mechanical defects. The elevator trim was found in the full nose-down position. The performance section of the Operating Handbook was reviewed with the pilot, the Chief Pilot and company owner. Using the gross weight alleged by the operator, and taking into account density altitude, runway surface, winds and surrounding terrain, it was found that the required takeoff distance approximated the available takeoff distance, assuming ideal pilot technique. The pilot had about 400 hours total time with about 70 hours on type. The a/c was released to the owner and his insurance company, which will remove the a/c from the site for salvage.