From the Alaska Department of Fish and Game: As their name implies, <Golden-crowned Sparrows> have a dull yellow stripe on their head, widely bordered on either side by black stripes. If seen from a distance, the unstreaked gray breast and similar size may cause confusion with the white-crowned sparrow. The descending three-note whistled song is quite distinctive and easily remembered. This bird is a fairly common nester in willow and alder thickets and can sometimes be found in the same habitat as the white-crowned sparrow. Four to five eggs are usually laid in a nest built on the ground.
Patchy forests or brush thickets.
I've heard this distinctive 3-note song absolutely every time I've gotten outside here in Alaska. However, this is a very elusive bird for photographs (in my experience).