These are the birds which chase the waves in and out on the beaches. They frequently give flight, forming a compact flock or, conversely, a long line of birds following the surfline. They lack any head pattern which would suggest a plover. They do, however, have a distinctively black bend of wing. This appears similar to the patches on the side of the breasts of Snowy Plovers.
Semipalmated Plovers are also common on the beaches of the Pacific Northwest.
Breeding adults have bright orange legs and a complete breastband. Juveniles and winter adults have duller legs and a brownish breastband. The bills of Semipalmated Plovers are much shorter and stubbier than those of Snowy Plovers. Vagrant juvenile Mongolian Plovers are similar to juvenile Snowy Plovers. Mongolian Plovers are larger, browner on the upperparts, have a larger bill, and usually have a complete brownish breastband, washed with buff.