Suggest a vacation trip for a couple based in California who love spending time outdoors

The American west is home to spectacular national parks. The national parks in California, Utah and Arizona are unique in their variety of landscapes and ecology. One possible trip is to Yosemite, Sequoia and Death Valley National Parks.  All of these parks provide a range of options for people of varying abilities. For the hardcore hikers a multi-day backpacking trip along the John Muir trip would take them through some of the most scenic mountain terrain in the country. Day hikers have dozens of shorter trails to choose from in each park. One point to keep in mind is that Death Valley would be uncomfortably hot in the summer months - May through September.