California State Route 198

State Route 198 is an east - west state highway that begins at U.S. Route 101 south of King City and ends in Sequoia National Park. It connects the California Central Coast to the mid–Central Valley through Hanford and Visalia, although the most developed portion is in the Central Valley itself. SR 198 intersects the major north - south routes in the Central Valley, including Interstate 5, SR 33, and SR 99. The highway that would become SR 198 was approved for construction in the 1910s through three bond issues, and was added to the state highway system in 1934. Parts of the highway were upgraded to freeway during the 1960s. Another portion was converted to an expressway in between Hanford and Visalia, and was completed in late 2012.Route descriptionThe road begins at a remote interchange with US 101 south of King City in the Salinas River Valley. Leaving US 101, SR 198 passes through the Priest Valley, climbs the Diablo Range as a two-lane road and crosses over an unnamed pass. It then descends along Warthan Canyon to the town of Coalinga in the agricultural Central Valley, where it briefly runs concurrently with SR 33. On both sides of Coalinga the road passes through the enormous Coalinga Oil Field.