I'm a little prejudiced geographically - LOL! But the Nor-Cal/Oregon Redwoods pretty much rock... They are also accompanied by a delightful twisty drive between them and moving inland roughly east on Highway 199. The Avenue of the Giants is amazing. Swing into any wide place and follow trails to giant trees.
http://www.redwoods.info/showrecord.asp?id=513
some spectacular swimming holes along the Smith River await as well. Park at the cut-off for Stout Grove (paved) and go straight down the trail to the water. Probably 40 or 50 feet deep, clear, clean with a sandy beach, huge rocks to jump off of and campground type rest room a few yards back from the water.
If your vehicle can handle a dirt road, turn toward Stout Grove and take Howland Hill road.
http://www.360cities.net/image/redwood-forrest-usa
It is wholly accessible, even with a two-wheel drive but it is gravel. Fabulous trees and trails through there. Boy Scout tree is a nice hike. That road will drop you out on the coast near the Indian Casino near crescent city. Alot of people make a loop - Avenue of the Redwoods to the cut off for Stout Grove, then Howland Hill road or some variation.
Jedediah Smith State Park looks promising but honestly doesn't have any where near the fabulous trees the other two routes give you for free.
angela
Oh - here's the swimming hole mentioned above and a stump from one of the trees on Howland Hill road (don't worry, plenty of bigger ones that are still TREES!):
