Meant to add, another great area in spring is the Columbia River Gorge east of Portland. The melting snow from the Cascades makes the many waterfalls on the Gorge's walls very impressive; depending on the precise time, the Hood River Valley can offer fabulous spring orchard flowers, with Mount Hood towering behind. Farther east, the Palouse wheat growing region of Washington State (as in Appaloosa horses) is a stunning panorama of green hills. Plus in two weeks you could hit Olympic National Park in Washington (rain forests, amazing rocky coast) plus the cities of Seattle and Portland, as well as Vancouver. I'd probably fly to PDX (cheap from LAX) and get a car there, make a loop out of it to avoid high one-way drop charges.