A Learjet 35 crashes into Smarts Mountain near Dorchester, New Hampshire, killing both pilots on board.

The Learjet Model 35 and Model 36 are a series of American multi-role business jets and military transport aircraft manufactured by Learjet between 1973 and 1993. When used by the United States Air Force, they carry the designation C-21A. Learjet was acquired by Bombardier Aviation in 1990 and is now a subsidiary, so the aircraft is also known as the Bombardier Learjet 35.

On Christmas Eve 1996, a Learjet 35A business jet disappeared near Dorchester, New Hampshire, United States. The crash led to the longest missing aircraft search in the state's history, lasting almost three years. Media attention eventually resulted in congressional legislation mandating improved emergency locator transmitters (ELTs) be installed in U.S.-registered business jets.

Smarts Mountain is a 3,238-foot-high (987 m) mountain in the town of Lyme in Grafton County, New Hampshire, United States. Smarts is flanked to the north by Mount Cube, at 2,909 feet (887 m), and to the southwest by Holts Ledge, at 2,110 feet (640 m). Although of only moderate elevation, Smarts is separated from the southwestern White Mountains by Oliverian Notch, a fairly low pass traversed by New Hampshire Route 25 southwest of Mount Moosilauke. That gives Smarts a relative height of 2,190 ft (670 m), which makes it one of twelve mountains in New Hampshire with a prominence over 2,000 ft (610 m).

Dorchester is a town in Grafton County, New Hampshire, United States. The population was 339 at the 2020 census.