As the highest mountain in the lower 48 states, California's 14,505-foot Mt. Whitney is on the "life list" for many hikers. And it's no wonder: The views from the top of the 21-mile round-trip Mt. Whitney Trail are unbeatable, extending across the jagged granite peaks of the Sierra Nevada to the expansive Owens River Valley and beyond. While tremendously rewarding, this hike is demanding even for experienced trekkers. Would-be hikers need to be prepared for the altitude, long distance, elevation gain, mountain weather, and other potential dangers.One Best Hike: Mt. Whitney by experienced hiker and author Elizabeth Wenk is a step-by-step guide that will tell you exactly how to tackle this trip with confidence.