Interstate 90 (abbreviate I-90) is the longest interstate highway in the United States at nearly 3,100 miles (5,000 kilometers). It is the northernmost east-to-west, coast-to-coast interstate. Its western terminus is in Seattle, Washington, at 4th Avenue S. next to Safeco Field and Qwest Field, and its eastern terminus is in Boston, Massachusetts, at Route 1A near Logan International Airport. It crosses the Continental Divide just east of Butte, Montana.