Sighting Record for Utah

Common name:	Tennessee Warbler
Scientific name:	Leiothlypis peregrina
Date:	Jul 17, 2016
Time:	2:10 PM
Length of time observed:	~1 minute
Number:	1
Age:	Probably adult
Sex:	female
Location:	Alta Town Hall
County:	Salt Lake City
Latilong:
Elevation:	8,500'
Distance to bird:	25'
Optical equipment:	8x42 binoculars
Weather:	Sunny and clear
Light Conditions:	mid day, well lit
Description: Size of bird:	small
(Description:) Basic Shape:	warbler
(Description:) Overall Pattern:	yellow and white
(Description:) Bill Type:	sharp dagger-like
(Description:) Field Marks and Identifying Characteristics:	Female type bird was all yellow with a pale yellow/white eye-line. On initial look I thought it was an OCWA, but in binoculars the color was off. It was a more lemony-yellow, than a dull yellow-gray. The bird popped into the open and had snow white undertail coverts. I was guiding a client and attempted to get him on the bird, as it flew down the hill, and then disappeared across the road to the south.
Song or call & method of delivery:	none
Behavior:	foraging in a willow
Habitat:	In Alta "city", on mountain hillside with aspen, and willow, as well as various other trees and plants.
Similar species and how were they eliminated:	Orange-crowned Warbler has yellow undertail coverts, and the tone of the yellow was different. Warbling Vireo isn't really yellow to this extent in any plumage, and had a thicker bill that is shaped differently.
Previous experience with this & similar species:	Have seen all on a variety of occasions.
References consulted:	None.
Description from:	Notes made later
Observer:	Tim Avery
Observer's address:
Observer's e-mail address:	**
Other observers who independently identified this bird:
Date prepared:	Aug 30, 2016
Additional material:
Additional comments:	There are only a couple July records west of the Rockies (south of Canada) in July on eBird. One from eastern Washington on July 19, one from California on July 9, and another from western Idaho on July 5. This species breeds in northern Montana in and around Glacier NP, so there are a lot of sightings from that area that I'm not including. Conceivably this is an early southbound migrant.