CA20 is the most recommended route from I5 (Central Valley) to US101, the Redwood coast highway. Taking that bypasses the pass on I5 at the state line.
Beware that 140 from Nevada to Oregon crosses some of the most remote part the country, with spotty gas. And there is a significant grade over a rim just after the state line (the kind that gliders like to use).
140 and 199 were billed at one time as a special route to the coast, and there may still be some signs and websites highlighting it.
Winnemucca to the SeaSo if you are coming to this part of Oregon via Winnemucca and 140, then 199 is the logical way to the coast. And there's plenty to see in the Medford/Grants Pass area before crossing the coast mountains. Your question is inspiring me to think of a spring trip to this area.