How many contiguous states, in the United States of America, are situated on its western coast?

Three contiguous states comprise the west coast of the United States. California, Oregon, and Washington.

The west coast of the United States, also known as the Pacific Coast, Pacific states, and the western seaboard, is the coastline along which the western United States meets the North Pacific Ocean. The term typically refers to the contiguous U.S. states of California, Oregon, and Washington, but sometimes includes Alaska and Hawaii, especially by the United States Census Bureau as a U.S. geographic division.

Though home to almost 40% of the U.S. population, the coastal areas account for only 10% of the contiguous U.S. land area.