State Route 503, also known as the St. Helens South Roadway, is a state route through the state of Washington. It has a spur route, State Route 503 Spur. It has a Southern terminus at State Route 500

Washington State Route 500

State Route 500, commonly known as SR 500, Highway 500, or 500, is a Washington state highway located in Clark County, Washington, United States.-Route description:...

 and a Northern terminus at Interstate 5

Interstate 5 in Washington

Interstate 5 in Washington is a highway in the U.S. state of Washington that extends from its border with Oregon to its border with Canada...

.

Route description

SR 503 starts at an exit and goes south until it reaches the NW Pacific Hwy. and turns NE on Lewis River Road. Then, SR 503 splits into a main highway and a spur; the main highway goes south on Yale Bridge Rd. Lewis River Road continues as State Route 503 Spur to Mount Saint Helens. Yale Bridge Rd. going south turns west onto NE 419th St. Next, SR 503 goes south on NE Gerber-Mckee Road and then turns southwest on NE Chelatchie Road. Then, SR 503 turns south on NE 216th Avenue, and then turning west at NE Fargher Lake Hwy. Next, 503 heads south on NE Lewisville Hwy that changes into SW 10th Ave. It ends at the State Route 500

Washington State Route 500

State Route 500, commonly known as SR 500, Highway 500, or 500, is a Washington state highway located in Clark County, Washington, United States.-Route description:...

 intersection.

Major intersections

County	Location	Mile	Destinations	Notes
Clark Clark County, Washington Clark County is a county located in the southwestern part of the U.S. state of Washington, across the Columbia River from Portland, Oregon.Clark County was the first county of Washington, named after William Clark of the Lewis and Clark Expedition...	Orchards Orchards, Washington Orchards is a census-designated place in Clark County, Washington, United States. The population was 17,852 at the 2000 census.-Geography:Orchards is located at ....	0.00		Southern terminus
	Battle Ground Battle Ground, Washington Battle Ground is a city in Clark County, Washington, United States. The population was 17,571 at the 2010 census. According to the Washington State Office of Financial Management, Battle Ground ranked 4th of 279 eligible incorporated communities in population growth between 2000 and 2005.-Origin of...	7.87
Cowlitz Cowlitz County, Washington Cowlitz County is a county located in the U.S. state of Washington. As of the 2010 census its population was 102,410. It forms the Longview, Washington, Metropolitan Statistical Area which encompasses all of Cowlitz County. The county seat is at Kelso, and its largest city is Longview...		31.04	to Mount St. Helens National Volcanic Monument Mount St. Helens National Volcanic Monument Mount St. Helens National Volcanic Monument is a U.S. National Monument that includes the area around Mount St. Helens in Washington. It was established on August 27, 1982 by U.S. President Ronald Reagan following the 1980 eruption of Mount St. Helens. The 110,000 acre National Volcanic...
	Woodland Woodland, Washington Woodland is a city in Clark and Cowlitz counties in the U.S. state of Washington. Most residents live within Cowlitz County, in which the majority of the city lies. It is part of the 'Longview, Washington Metropolitan Statistical Area'...	54.11		Northern terminus

Spur route

State Route 503 Spur, abbreviated SR 503 Spur, is a small state highway

State highway

State highway, state road or state route can refer to one of three related concepts, two of them related to a state or provincial government in a country that is divided into states or provinces :#A...

 spur route in the U.S. state

U.S. state

A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...

 of Washington, connecting to Mount St. Helens

Mount St. Helens

Mount St. Helens is an active stratovolcano located in Skamania County, Washington, in the Pacific Northwest region of the United States. It is south of Seattle, Washington and northeast of Portland, Oregon. Mount St. Helens takes its English name from the British diplomat Lord St Helens, a...

. It has a western terminus at Yale Bridge Road (SR 503) and an eastern terminus at the Mount St. Helens National Monument border. SR 503 Spur continues as Forest Road 90 as it crosses into Skamania County. It is called Lewis River Road all the way. The spur route is 8.42 miles (13.55 km) long.