The western portion begins at Tipton at a junction with State Route 99 and heads east towards Porterville before ending at Quaking Aspen in the Sequoia National Forest.

The 43.0-mile[2] (69.2 km) portion over the Sierra Nevada remains unconstructed, and the California Department of Transportation (Caltrans) has no plans to build it through the wilderness areas.

The county-maintained Western Divide Highway continues south to a point west of Johnsondale, where traffic can turn east to reach US 395 via Sherman Pass and County Route J41.

Crossing several ridges to the northeast, SR 190 would make its way to the South Fork Kern River near Monache Mountain, then heading southeast along that waterway to the vicinity of Haiwee Pass.

It leaves the valley to the southeast alongside Furnace Creek Wash, where the highway is usually closed at least once a year by flash floods.

SR 190 turns east away from the wash at the turnoff to Dante's View, and soon leaves the park, after which it follows a mostly straight alignment to its end at State Route 127 at Death Valley Junction.

[8] Except west of State Route 65 in Porterville, SR 190 is eligible for the State Scenic Highway System;[9] the part within Death Valley National Park has been added to the system by the California Department of Transportation,[10] meaning that it is a substantial section of highway passing through a "memorable landscape" with no "visual intrusions", where the potential designation has gained popular favor with the community.

After several failures in getting a toll road approved from Lida, Nevada or over Towne Pass, he scaled back plans to include only the part of the latter route between southeast of Darwin and his resort at Stovepipe Wells.

[18] The state Division of Highways and National Park Service soon paved the route from Lone Pine (on US 395) through Towne Pass and Death Valley to Baker (on US 91).

[33] Also in 1959, the original routing from Lone Pine through Death Valley to Baker was added to the proposed California Freeway and Expressway System, though no parts have been upgraded as such.

[39][40] Except where prefixed with a letter, postmiles were measured on the road as it was in 1964, based on the alignment that existed at the time, and do not necessarily reflect current mileage.