The first team to utilize this ballpark for spring training was the Seattle Rainiers in 1950... a Pacific Coast League team. This was a big deal, because at this time the "Triple-A" (then known as Class A) Pacific Coast League was under consideration of becoming another Major League like the American and National League. By 1957, the westward migration of teams from Philadelphia, New York and Brooklyn would satisfy the need for Major League Baseball on the west coast.