This stunning National Park in the Cascade Mountains of northern Washington, also known as the Alps of America, is definitely one of my favorite places on earth. It's one of the least visited National Parks in the US, partly due to the difficulty of access. While the park is just two hours from Seattle, the only way to reach the stunning alpine regions is by trail, starting at a minimum of 7 miles and 2,000 foot elevation change. My favorite trail, Cascade Pass & Sahale Arm, clocks in at 13 miles and 3,500 foot elevation change, and the toughest hike I've done so far -- Thornton Lakes -- was 14 miles and 4,000 foot elevation change. No matter how sore the legs are afterward, it's totally worth the effort as you climb higher and higher with rugged mountains and glaciers spreading out as far as the eye can see in some of the most spectacular mountain scenery in the world.