General: 3.5 to 4 inches in length.

Adult Male: Rufous head, back, flanks, rump, and tail. Bright orange-red iridescent gorget. White breast and midbelly area. Occasionally has variable amounts of green on the back and crown, which can make it look similar to the Allen's Hummingbird. Black feet. Long, thin black bill.

Adult Female: Green upperparts. White underparts. Rufous flanks. Small group of red spots at the center of greenish spots on the throat. Tail feathers are rufous with black tips and the outer three feathers on both sides have additional white tips. Black feet. Long, thin black bill.

Immature: Immature male similar to female, except lacks white tips on outer tail feathers and lacks central throat spots. Immature females lack central throat spots.

Coniferous, broadleaf, and riparian woodlands. Mountain meadows.

Nesting

2 white eggs. The incubation period is 12-14 days. Fledging occurs 20 days after hatching. The nest is a tiny open cup made from lichens, plant down, and spiderwebs. Typically built on a horizontal branch. They breed at higher latitudes than any other species of hummingbird, from northern California to southeastern Alaska.