Crescent City is in Del Norte County in the northwestern corner of California. You can get in Crescent City from San Francisco or Portland, US Highway 101 makes a scenic but sometimes slow drive along the coast to Crescent City. Between San Francisco and Crescent City, there are no good connector roads from the east, so if you want to take 101, you need to start from the San Francisco Bay Area far to the south.
From Grants Pass in Oregon, you can take US Highway 199 southwest to reach Crescent City. Grants Pass is also a stop along Interstate 5, which is the major north-south highway on the west coast. Interstate 5 is known as fast and easy to drive and has good connections to further east, but it's often a boring road.