On September 6, 1997, about 1900 Alaska daylight time, a Cessna 207A airplane, N7318U, crashed during takeoff from a remote, private airstrip at Canyon Creek, Alaska, about 65 miles east of Bethel, Alaska. The airplane was being operated as a visual flight rules (VFR) on-demand passenger flight under Title 14 CFR Part 135 when the accident occurred. The airplane, operated by Yukon Aviation, Bethel, sustained substantial damage. The certificated commercial pilot, and three passengers, were not injured. Visual meteorological conditions prevailed. VFR company flight following procedures were in effect. The operator reported the airplane was transporting passengers from the Canyon Creek airstrip that is 1,000 feet long and 40 feet wide, at an elevation of 1,200 feet mean sea level. The gravel airstrip is oriented on a 130/310 degree heading. The airplane became overdue, and the operator dispatched another airplane to the airstrip. The search airplane's crew located the accident airplane off the end of the runway. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on September 7, 1997, about 1400, the pilot reported he departed on a 130 degree heading, and lifted off the airstrip near the end of the runway. After liftoff, the pilot indicated the airplane climbed to about 50 feet above the ground, and suddenly encountered a downdraft. The airplane began descending toward the ground, and collided with rough terrain. The airplane came to rest in a small creek, and received damage to the nose wheel, propeller, right elevator, and right wing. The pilot reported in the NTSB pilot/operator report (NTSB form 6120.1/2), that the airstrip is located in a narrow canyon with steep terrain on the north side, and lower hills on the south side. The pilot indicated the local weather conditions consisted of: Sky condition and ceiling, 10,000 feet scattered; visibility, 40 statute miles; temperature, 55 degrees F; wind, 040 degrees at 20 knots, with gusts to 25 knots.