On July 16, 1994, at 1200 Alaska daylight time, a wheel equipped Cessna 206 airplane, registered to and operated by Northwestern Aviation of Kotzebue, Alaska, struck a "cut bank" while landing on a gravel bar on the Kelly River, 100 miles north of Kotzebue. The Air Taxi flight, operating under 14 CFR Part 135, departed Kotzebue on a VFR flight plan and the destination was the accident site. Visual meteorological conditions prevailed. The pilot and the passenger were not injured and the airplane was substantially damaged. According to the pilot, he had landed on the gravel before but he still "dragged" the strip three times before this landing. He dragged the strip each time at a lower altitude ending with 500 feet. He could not see the "cut bank" during his observations of the landing area. During the roll out the airplane struck the cut bank. The cut bank was approximately 3 to 4 feet deep and was composed of the same material as the rest of the gravel bar. The airplane's nose gear sheared just above the fork attach points and the main landing gear was pushed rearward causing damage to the fuselage gear box attaching structure. According to information provided by the Federal Aviation Administration Airman Certification Branch in Oklahoma City, Oklahoma, the pilot applied for an additional aircraft category rating on May 6, 1994. The pilot listed that he had a total time of 3800 hours in airplanes and 35 hours in helicopters. He was issued a rotorcraft/helicopter rating which fulfilled the additional requirement for a Biennial Flight Review.