On October 2, 1970, Martin 404, N464M, was operated for the purpose of transporting the Wichita State University football team from Wichita, Kansas, to Logan, Utah. Following a refueling stop at Denver, Colorado, the flight proceeded via a "scenic" route up Clear Creek Valley, toward Loveland Pass (elevation 11,990 feet mean sea level) and the Loveland ski resort area. The mountains on either side of the flight path ranged from 12,477 feet m.s.l. t o 13,234 feet m.s.l. At approximately 1300 m.d.t., the aircraft crashed into the base of Mount Trelease, 8 miles west of Silver Plume, Colorado. The elevation of the crash site is 10,750 feet m.s.l. Of the 40 persons on board, 30, including the captain and a stewardess, received fatal injuries. Two of the surviving passengers later succumbed to injuries received in the crash. Investigation revealed that the aircraft first struck the tops of trees at an elevation of 10,800 feet m.s.l. in a heavily wooded area. The aircraft continued on a heading of 215� magnetic, on a 4� descending flight path, for a distance of 425 feet from the point of initial tree contact. The a ircraft was destroyed by fire and impact. Subsequent teardown of the engines and examination of the propeller mechanism showed that both engines were producing power at impact. Weather conditions i n the crash area and along the flight path from Denver, Colorado, to Logan, Utah, were reported to have been clear. There were no known reports of turbulence, or up- and downdraft activity, and none was recalled by the surviving copilot or passengers. Eyewitnesses located at about the 11,900-foot elevation at Loveland Pass were looking down at the aircraft when it came into view around Mount Sniktau. Angular measurements made from their viewpoint, and the testimony of most other witnesses, indicated that the aircraft was at approximately 11,000 m.s.l in the vicinity of Dry Gulch. The valley width in the area immediately west of Dry Gulch os 3,000 feet at the 11,000-foot contour.