I'm not sure how many records there are for this species from land, but my guess would be in the 20-30 range. Which is surprising considering that it's a regular migrant offshore in both the spring and fall. A few of the local old-timers hadn't seen this species yet - thankfully it remained in the area for the entire day allowing many of the local birders to see it.
In comparison to kittiwakes, notice the shorter wings. Some of the field guides mention a longer tail, not something I noticed today in the field.
I assume the grey mantle indicates new feathers? They contrasted with the old browner feathers of the inner-wing.
Aged as a 1st winter by the black tail band, and the brown colour to the inner-wing.
Sabine's Gulls are one of few two-year gulls.
Can you see the birders?