This individual was reported by others still at the Larimer County landfill on 21 and 22 April. I was able to obtain more digiscoped photos on 23 April.
image adjusted
image adjusted
with first-cycle Glaucous Gull, Ring-billed Gull and California Gulls
with first-cycle Glaucous Gull, California Gulls and a faded Herring Gull (possible "Nelson's" Gull)