and 129 bald eagles have been observed heading east. From mid-September through October, a similar migration occurs, but in the opposite direction. This is also a migration route used by other raptors such as northern goshawks, red-tailed hawks, and rough-legged hawks. Canada geese, tundra swans, and snow geese also use the pass during migration periods. The golden eagles and other birds can be observed from a distance as close as . Climate According to the Köppen climate classification system, Rogers Pass has a humid continental climate, abbreviated "Dfb" on climate maps. Summers tend to be warm to hot, with cooler nighttime temperatures, while winters are very snowy and cold, sometimes severely cold. Precipitation peaks during late spring and early summer. Record-cold temperature Rogers Pass is the location of the lowest temperature ever recorded in the contiguous United States. On January 20, 1954, a low temperature of was recorded during a severe cold wave. Only Alaska, Antarctica, Canada, Greenland, China and Russia have recorded lower temperatures. Since the establishment of the modern weather station in 1964, however, the temperature has not fallen below . See also List of mountain passes in Montana List of weather records A.B. Rogers Lewis and Clark Pass (Montana) Rogers Pass (British Columbia) Cited references Landforms of Lewis and Clark County, Montana Mountain passes of Montana