Real hummer

In Lewis' typically short notation style, he mentions coming across the nest of a hummingbird.  The nest is found on June 15, 1806, in the Idaho Rockies, and there are eggs in it.  Strangely, there is no mention of adult hummingbirds, which are quite territorial.  In fact, the male broad-tailed hummingbird is known for producing a trilling sound as it flies, so they are often heard first and then seen.  Neither is there even the briefest description of the eggs sitting in that nest, which would make identifying the bird more definite.

To say Lewis discovered the nest of a broad-tailed hummingbird is, well, pretty much a guess. These hummers are true mountain birds, and the party was in the the Bitteroot range, a known habitat for broad-tailed hummingbirds.  That much fits.  However, Idaho has other resident hummingbird species, too.  There is the widespread rufous hummingbird, the black-chinned, and less frequently, Anna's.  Nevertheless, it is rather inconceivable that the party should pass over the Rockies without witnessing the iridescent splash of the broad-tailed hummingbird.