By the time the U.S. reached the west coast, Russia had already colonized the Alaska through their territories in far-east Asia, that gave them a natural claim upon the west coast, but it was very distant from the developed part of Russia and Alaska was difficult to settle, so the U.S. bought the Alaska territories from them in 1867.
D. Spain. The Spanish explorers were the first Europeans to reach the west coast of North America, om the Pacific coast in 1513.
