We counted migratory shorebirds and documented their patterns of shoreline distribution at Mono Lake in the Great Basin of California via annual spring and fall surveys from 1989 to 1995. We tallied a total of 30 species—29 in fall, 25 in spring, and 24 in both seasons. Median counts of all shorebirds were 31,432 (13,901–50,916) in fall and 7,792 (2,683–25,616) in spring. Median counts exceeded 5,000 each for the American Avocet and Wilson’s and Red-necked phalaropes in fall, and 1,000 for the Western and Least sandpipers in spring. Of nine species with median counts of >50 individuals, medians were more than 50% higher in fall than spring for the American Avocet, Wilson’s Phalarope, and Red-necked Phalarope; more than 50% higher in spring than fall for the Semipalmated Plover, Western Sandpiper, Least Sandpiper, and Dunlin; and similar in both seasons for the Snowy Plover and Killdeer.