Interstate 5 in Washington in the context of "High-occupancy vehicle lane"

Downtown is the central business district of Seattle, Washington. It is fairly compact compared with other city centers on the U.S. West Coast due to its geographical situation, being hemmed in on the north and east by hills, on the west by Elliott Bay, and on the south by reclaimed land that was once tidal flats. It is bounded on the north by Denny Way, beyond which are Lower Queen Anne (sometimes known as "Uptown"), Seattle Center, and South Lake Union; on the east by Interstate 5, beyond which is Capitol Hill to the northeast and Central District to the east; on the south by S Dearborn Street, beyond which is Sodo; and on the west by Elliott Bay, a part of Puget Sound.

Mount Vernon is the county seat of and the most populous city in Skagit County, Washington, United States. A central location in the Skagit River Valley, the city is located 51 miles (82 km) south of the Canadian border and 60 miles (97 km) north of Seattle. The population was 35,219 at the 2020 census, making it the 35th most-populous city in Washington, with 62,966 people living in its urban area. It is one of two principal cities of and included in the Mount Vernon-Anacortes Metropolitan Statistical Area, covering most of Skagit County.

Mount Vernon and its surrounding areas is known for its annual Skagit Valley Tulip Festival, which has Mount Vernon host a street fair in downtown once a year, with millions of tulips grown in the Skagit Valley every year. Between the 2000 and 2020 census, Mount Vernon grew by 34.3%, and is a prominent location in Northwestern Washington, connected to neighboring communities via I-5 and Amtrak (with Skagit Station).

State Route 104 (SR 104) is a 31.75-mile-long (51.10 km) state highway in the U.S. state of Washington, serving four counties: Jefferson on the Olympic Peninsula, Kitsap on the Kitsap Peninsula, and Snohomish and King in the Puget Sound region. It begins south of Discovery Bay at U.S. Route 101 (US 101) and crosses the Hood Canal Bridge over Hood Canal to the terminus of SR 3 near Port Gamble. SR 104 continues southeast onto the Edmonds–Kingston Ferry to cross the Puget Sound and intersects SR 99 and Interstate 5 (I-5) before ending at SR 522 in Lake Forest Park. SR 104 also has a short spur route that connects the highway to SR 99 at an at-grade signal on the Snohomish–King county line.

Established during the 1964 state highway renumbering, SR 104 was formed out of four highways, themselves created in 1937: Secondary State Highway 9E (SSH 9E) from Discovery Bay to Port Gamble, Primary State Highway 21 (PSH 21) from Port Gamble to Kingston, SSH 1W within Edmonds, and SSH 2B from Edmonds to Lake Forest Park. PSH 21 was originally part of State Road 21, added to the state highway system in 1915 to connect the Port Gamble–Shine ferry to the Kingston ferry landing. The Edmonds–Kingston ferry at the end of State Road 21 has been in operation under various companies since 1923 and was served by the 14-car City of Edmonds. SSH 9E extended from Discovery Bay to Port Ludlow initially and was moved south and extended to the South Point ferry landing in the late 1940s. The bridge replaced the South Point–Lofall ferry when it opened in 1961, but the ferry was re-used during the construction of the second Hood Canal Bridge after the first bridge sank in 1979 and before the new bridge opened in 1982. The Edmonds–Kingston ferry was added to the state ferry system in 1951 before it was incorporated into SR 104 in 1994.