At about 2000 Alaska time, a Cessna 207 struck terrain during cruise flight about four miles southeast of Marshall. The pilot suffered serious injuries. The airplane was equipped with Capstone equipment, which uses GPS, a terrain database and a multifunction display to portray terrain threats. The pilot said he was experiencing a strong headwind and turbulence and the Capstone display was almost completely red just before impact. The airplane was located about 1,200 feet msl on the north side of a 1,714-foot ridgeline.