Organized whale watching started in the United States, when the Cabrillo National Monument in San Diego was declared a public venue for observing the migration of Gray Whales; the spectacle attracted 10,000 visitors in its first year, 1950.^[1] In 1955 the first water-based whale watching commenced in the same area, charging customers $1 per trip to view the whales at closer quarters.^[1] The industry spread throughout the western coast of the United States over the following decade.^[1]