The broad-tailed hummingbird is a western counterpart of the eastern ruby-throated hummingbird.  Broad-tails are usually found in mountain forests in summer, and most migrate south of the US during the winter.   Males have brilliant rose-red gorgets; females have rusty sided and small streaks on the throat.   I took most of these photos at a very nice Forest Service rest area in the Cache National Forest in northeastern Utah; others were made in the mountains of Colorado.