“For several years we have conducted the hawkwatch migration site count near Eureka AK (Southcentral). I’m not certain of the relative abundance of W. RTs in your area. Up here Westerns are rare and some people question if they occur here at all. Harlan’s are quite common with several hundred counted each spring. Consistently, year after year, the ratio of light morph to dark morph Harlan’s is close to 8% rather than the previously thought 1%. I believe your first conclusion - an immature light morph Harlan’s - was correct.

The very clean white throat, streaking, overall whitish head (supercilium and auricular), scant markings and overall clean appearance on the underparts (with the exception of patagium, belly band and comma). Typically, Harlans’ dark colors (dorsal and ventral) tend toward gray/black/coal (rather than chocolate brown of a typical RT). I can’t discern that by the photos but it may help you. The only thing that I see that suggests RT is the markings on the leg feathering - these are normally clean on a Harlan’s. What did you see on the dorsal tail? If there was any blotchiness/irregularity, whitish patches, vs the consistent even fine brown barring of a regular RT, that would also suggest Harlan or Harlan’s hybrid. Of course there is much variation between light, intermediate and dark morphs of Harlan’s and W RT as well as hybridization between the subspecies so they cannot all be conclusively ID’d - but its fun to try!”