Traveling up and down, but mainly up, over 28 miles of mountains and canyons between Del Valle and Sunol, the Ohlone Wilderness Trail will make you hurt. More specifically, it will make your ass hurt. One member of the Cal Hiking and Outdoor Society complains that the trail wanders over contours "in reckless disregard for human endurance." Indeed, endurance -- and two or three days -- is what you will need for this hike. Make this trip in the spring, when the rolling hills of Del Valle, above Livermore, are a lush green, and the forested fire trail is shady and cool. If you do it in the summer, when the grass is dry and withered, you too will feel like dying. But your efforts will be rewarded by a backcountry experience unmatched in the East Bay, vibrant wildflower-filled meadows, and few encounters with other humans. You'll even get some elevation: The trail scales Rose Peak, which, at 3,817 feet is only 32 feet below the summit of Mount Diablo, but is nowhere near as popular because of its remote location. Take a side trip to Murietta Falls, the highest waterfall in the Bay Area, and finish the trek in Sunol, where you should have a second car waiting.