This is the world's smallest "peep" and can usually be picked out by its brownish coloration, dull yellowish legs, and hunched, creeping foraging style. Least can be found in small flocks in Oregon almost year-round.
The Least sandpiper feeds on open mud with Western sandpipers but often feeds where some grass, salicornia or other cover is present, avoiding walking in the water as Western often do.
It is uncommon to locally abundant statewide in migration, with most birds along the coast and at larger lakes and marshes inland. It is locally common on the coast in winter; smaller numbers winter in the western interior valleys, where small flocks can be found at larger lakes, locally in flooded fields and sometimes even at marginal sites such as sewage ponds. A few birds winter east of the Cascades where appropriate habitat remains open.