These impressive, large, pale gulls were uncommon on our visit. Four subspecies are usually recognized. This is L. h. pallidissimus which breeds from the Taymyr Peninsula east to the Bering Sea, wintering from northwest China east to Japan. It is the largest, biggest billed, and palest subspecies. Note short wing-tip projection beyond the tail, decidedly less than length of bill on this adult. This can help distinguish them from the similar but much smaller Iceland Gull (L. g. glaucoides). Canon PowerShot SX60.
References:
Burger, J., Gochfeld, M. & Garcia, E.F.J. (2019). Glaucous Gull (Larus hyperboreus). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from https://www.hbw.com/node/53979 on 18 March 2019).
Howell, S.N.G. and Dunn, J. (2007) A Reference Guide to the Gulls of the Americas. Peterson Field Guides, New York.
Malling Olsen, K. & Larsson, H. (2003) Gulls of Europe, Asia and North America. Christopher Helm, London.
Weiser, E. and H. G. Gilchrist (2012). Glaucous Gull (Larus hyperboreus), version 2.0. In The Birds of North America (A. F. Poole, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bna.573