In Idaho, an estranged couple are trapped in a blizzard while on vacation just before Christmas.

Rodeo cowboy Jack and ranch hand Ennis are hired as sheepherders in 1963 Wyoming. One night on Brokeback Mountain, they spark a physical relationship. Though Ennis marries his longtime sweetheart and Jack marries a fellow rodeo rider, they keep up their tortured, sporadic love affair for 20 years.