Sightings:
- Little Gull (1st cycle). Nanaimo District, British Columbia. 02 October 2020.
- Lesser Black-backed Gull (2nd cycle type). Pierce County, Washington. 02 October 2020.
- Slaty-backed Gull (adult). Toronto County, Ontario. 03-14 October 2020.
- Same individual from nearby Mississauga County from September 2020.
- Lesser Black-backed Gull (adult). Peace River District, British Columbia. 06 October 2020.
- Heermann's Gull (3rd cycle). Pima County, Arizona. 07 October 2020.
- Heermann's Gull (1st cycle). Lake County, Montana. 11 October 2020.
- 2nd State Record.
- Ross's Gull (adult). Kenai Peninsula County, Alaska. 16 October 2020.
- Apparent 2nd Record for the Kenai Peninsula.
- Little Gull (adult). Kitsap County, Washington. 16 October 2020.
- Laughing Gull (1st cycle). St Joseph County, Michigan. 17 October 2020.
- Black-legged Kittiwake (adult). North Interlake Area County, Manitoba. 17 October 2020.
- California Gull (1st cycle). Anchorage County, Alaska. 17 October 2020.
- California Gull (3rd cycle). Nome County, Alaska. 17 October 2020.
- Apparent 1st Record for Bering Sea region.
- California Gull (adult). Jefferson County, Wisconsin. 19 October 2020.
- Slaty-backed Gull (adult). Benton County, Washington. 19 October 2020.
- Presumably a returning bird since winter of 2016.
- Sabine's Gull (1st cycle). Ashland County, Wisconsin. 20 October 2020.
- 1st County Record.
- Lesser Black-backed Gull (ad., 2nd cycle). Wasco County, Oregon. 20 October 2020.
- Heermann's Gull (2nd cycle). Sarasota County, Florida, 21 October 2020. 21 October 2020.
- Black-headed Gull (adult). Chatham-Kent County, Ontario. 23 October 2020.
- Black-tailed Gull (adult). San Francisco County, California. 23 October 2020.
- Black-legged Kittiwake (juvenile). Clinton County, Iowa. 25 October 2020.
- Heermann's Gull (3rd cycle). Maricopa County, Arizona. 25 October 2020.
- Little Gull (1st cycle). Grundy County, Illinois. 26 October 2020.
- Little Gull (2nd cycle). Miami County, Kansas. 26 October 2020.
- Lesser Black-backed Gull (adult). Lincoln County, Oregon. 26 October 2020.
- Lesser Black-backed Gull (4th cycle type). Skagway-Hoonah-Angoon County, Alaska. 27 October 2020.
- Slaty-backed Gull (adult). Clallam County, Washington. 28 October 2020.
Notes:
- 212 Lesser Black-backed Gulls were counted in Findlay, Ohio, on 17 October 2020. Guatam Apte and Jerald Reb reported approximately 40% of the flock consisted of adult type birds. This count is without question a new high for Lessers recorded anywhere away from the Atlantic.
- On 27 October, Amy Courtney found a subadult Lesser Black-backed Gull in Hoonah, Alaska. Several traits suggest an Asian taxon, but ruling out a European form is proving difficult.
- On 22 October, Christopher Coxson photographed a 1st cycle Iceland Gull in British Columbia that appears to be from the nominate subspecies, L g. glaucoides.