I first conquered Mt. Sanitas when I was training for the Pikes Peak Marathon in 2003. I had heard from a friend of a friend that it was a great hill workout and that it was quick and easy to get to.

I attacked the run with vigor, but the calf-grinding workout was more difficult than I expected. On the climb, I felt like I was on the stair master at the gym. I nearly lost the trail near the summit, and then I ended up scrambling on all fours during the icy descent. After one loop, I was toast.

Although you may think that running one loop at Mt. Sanitas is perfectly acceptable, that|s only because you|ve never met my neighbor John. Runners like John enjoy running loop after loop. After loop. His record is 11 laps around the 3.1 mile trail V a feat which took him nearly 11 hours. He set his personal record while another trail runner, Paul Pomeroy, was running 100 miles V which took more than 45 hours!

The Mt. Sanitas loop run begins at the base of Sunshine Canyon at 5,520 feet. The trail traverses the ridge line of Mt. Sanitas with a peak elevation of 6,863 feet. The trail then descends the eastern side of the mountain until it reaches the valley ,,(2) oor and connects with the Sanitas Valley Trail.

To get to Mt. Sanitas, drive north on Broadway Street in Boulder. Turn west on Mapleton Avenue. Drive past Fourth Street until you discover two small parking areas. The trail head is just moments away from the busy bustle of Boulder.

Trails from both parking areas will lead you to the main trail, the Sanitas Valley Trail, which is a wide dirt road. This is where you|ll finish your run, but to get your heart pumping, turn left at the first junction onto the Mt. Sanitas Trail.

Almost immediately you are greeted with a set of steep log steps, but this is just the beginning of the ascent to the top. The 1.4 mile climb gains almost 1,400 vertical feet for an average grade of 18 percent. Many of the local runners and ultrarunners do loops on Mt Sanitas as training for some of the hardest races in the country, such as the Pikes Peak Marathon and the HURT and Hardrock 100 mile trail races.

As you race up the steep trail, you may need to stop to catch your breath. While doing so, you can enjoy the views and ponder the history of the area. For instance, Mt. Sanitas was named for the sanitarium that used to stand at the base of the mountain.

When you reach the summit, you|ll be able to see Boulder to the east, the Indian Peaks wilderness area to the west, and the Flatirons to the south. Catch your breath, take a swig of water, and then continue your run down the steep, rocky trail on the mountain|s east ridge. Watch your footing. The trail reconnects with the smooth, wide path of the Sanitas Valley Trail. Follow the trail back to your car, or start the loop again.

Trail running greats like Dave Mackey and Galen Burrell have been known to sprint around the entire loop in less than 30 minutes. But be warned, it will take twice as long for mere mortals.

If you want to lengthen your run without running the loop again, there are several other trails nearby. One popular route follows the Dakota Ridge Trail, which parallels the Sanitas Valley Trail. If you cross the street where you parked, there are also numerous short trails.

The trails at Mt. Sanitas are part of Boulder Open Space and Mountain Parks. The area is free to use and is maintained by Boulder sales tax revenue. Biking is not allowed, but dogs are permitted and will be found in abundance. The area can be congested at times so don|t expect much solitude.