The range of this species is from Alaska to Mexico. It is similar in size and appearance to the Manila littleneck. It is a medium-size clam, oval to round in shape. The external surface is marked with concentric rings and radiating ridges which produce a cross-hatched appearance. The color is variable, but is normally cream or grey, and sometimes mottled with brown markings. The shells close completely. They have an external hinge ligament and the black siphon tips of native littlenecks are fused together. The inside edge of their shell has a fine, toothed-edge, easily seen and felt. They are found in the top 4-6 inches of substrate of gravel-mud in protected bays. Normally this clam is found somewhat higher in the tidal zone than butter clams, being concentrated at about mid tide level, but are sometimes found mixed with butter clams in the lower intertidal and subtidal zones. They occur subtidally as deep as 60 feet. Sport diggers normally use rakes, shovels or forks to obtain them. On very rare occasions they can form pearls.They are delicious when steamed open and dipped in hot butter. This clams does not live as long out of the water as the Manila. Commercially they are dug by hand and mechanical harvesters. They are sold primarily in the fresh market with a large percentage of the production shipped to California. The littleneck clam is important to sport and commercial interests.
Native littlenecks spawn in the spring and early summer. Water temperatures of 60° F have been used successfully to initiate spawning in the laboratory.