Lawrence Akutagawa wrote:

A better strategy would be to utilize Interstate 5 until you get into
Oregon, then head west to the coast. Follow the coast until you hit
Astoria, then head back east to Interstate 5. If time allows, make the
partial loop of the Olympic Peninsula. This routing will permit you to
visit/view - should you be so inclined - places like McArthur Burney Falls,
Mossbrae Falls, Oregon Caves, Mt Shasta, Castle Crags State Park, Crater
Lake, Oregon Sand Dunes, the many lighthouses along the Oregon coast,
Tillamook, the haystacks of Cannon Beach, Silver Falls state park, the
waterfalls along the Columbia River Gorge (including Multnomah Falls), a
replica of Stonehenge, Bonneville Dam, Mt. St. Helen, Mt. Hood, the Olympic
rain forest, the Olympic seashore, and Hurricane Ridge.

Hmm...this is a good itinerary, but it misses the California wine
country and the redwoods on 101.

I would probably opt for this rather than Interstate 5 through the Mount
Shasta region.