Known for its 25 major glaciers and snowcapped peaks, Washington's Mt. Rainier is – at 14,410 feet – the highest point in the lower 48. It's also an active volcano. Mountaineers flock to this spot, which is a convenient two hour drive outside of Seattle. There are 210 miles of trails inside the park that wind past 34 waterfalls and 62 lakes, most of which are surrounded by thick forests.
DON'T MISS: Hike the five-mile round trip on the Skyline Trail from Paradise to Panorama Point, which offers a breathtaking 360-degree view of wildflower meadows, Tatoosh Peaks, Mount Saint Helens and the Nisqually Glacier.