United Airlines Flight 610

On June 30, 1951, United Airlines Flight 610, a US transcontinental San Francisco–Oakland–Salt Lake City–Denver–Chicago service flown by the Douglas DC-6 aircraft Mainliner Overland Trail crashed in Larimer County, northwest of Denver. All 50 on board were killed.

After completing its first two segments, Flight 610 departed Salt Lake City at 12:11 a.m. en route to Denver. At around 1:47 a.m, Flight 610 reported to air traffic control that it had passed the Cheyenne radio range station, and requested a lower altitude, which was granted down to 8,500 feet.

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