“Route 830” was a U.S. Highway in Washington State, created in 1926 as part of the initial set of United States numbered highways. It ran for 232 miles between a junction with US-97 near Maryhill and a junction with US-101 near Naselle. 

The number suggests that US-830 was an auxiliary route of US-30, however they never connected and ran parallel to each other, with US-830 on the northern bank of the Columbia River and US-30 on the southern bank in Oregon. 

Until the mid-1930s the highway was not complete between Lyle and Maryhill. Traffic was routed northeast out of Lyle along what is now known as the Centerville Highway, ending at US 97 about four miles south of Goldendale (shown in blue on the map). In approximately 1933, US-830 was rerouted east of Lyle following the north bank of the Columbia River, with the endpoint at US-97 closer to Maryhill. It was co-signed with US-99 from Vancouver to Longview (the entire route shown in red on the map). 

US-830 was decommissioned as a U.S. Highway in 1968, however the roadway is still in use and is currently signed as SR (State Route) 14 between Maryhill and Vancouver, Interstate 5 between Vancouver and Longview, SR-432 for a short stretch through Longview, and SR-4 from Longview to the western terminus near Naselle. 

When it existed, US-830 was the highest numbered route in the U.S. Highway System (and remains the highest U.S. route number ever used). The highest numbered route still in existence is US-730 from Boardman, Oregon, to Wallula Junction, Washington.