Upon exiting the Indian territory, SR 140 curves northwest to parallel the Quinn River for about 10 miles (16 km) as it rounds the northern edge of the Jackson Mountains.

As the river turns southeast towards the Black Rock Desert, the highway continues its northwest trajectory through the valley between the Bilk Creek Mountains on the east and the Pine Forest Range to the west.

[2] At Denio Junction, State Route 140 turns westward past the south end of the Pueblo Mountains.

[2] The valley has been known for its black fire-opals, and some mining operations in the area will allow civilians to hunt for the precious stones for a fee.

[3] Near this valley, SR 140 enters the Sheldon National Wildlife Refuge, an area designed to provide habitat for pronghorn and conserve native fish, bird and plant species.

However, instead of entering Oregon en route to Adel, the road veered westward through Washoe County towards Vya and Cedarville, California.

Instead of following SR 8A to Vya, the newly paved road curved northwest to the Oregon border near the Humboldt-Washoe county line.

[13] This work completed the 117-mile (188 km) stretch of Winnemucca to the Sea Highway between Denio Junction and Lakeview, Oregon.