Lost Valley

Lost Valley

The name comes from the bootleggers who once made use of the area, getting lost among the numerous hollows. It was also near the site of an ammunition works and uranium processing plant which necessitated the cleanup that lies under the large mound on Hwy. 94. Now, the trail is a 10.5 mile loop with a mixture of double and singletrack punctuated with old homesteads, rock formations, natural springs, and a waterfall crossing. This is a very scenic and enjoyable mountain bike experience.

The gravel/doubletrack sections are fairly flat. The singletrack sections are super-flowy with punchy rock obstacles that will reward you with great views and better riding, the trail can get technical in spots and is now a much longer ride due to the increased singletrack. Be advised that this 10.5 mi loop will take some riders 2 hours to navigate due to the amount of singletrack and the difficulty of the rocky sections.  There is a central fire road that cuts the loop almost in half which can be used to shorten or lengthen your ride.

Trail surface varies from dirt to rock throughout the trail, and drains very well, except in the flats of the lower creek bottom.

The trail is open until 10 pm, so it's a good place to ride at night.


From the Highway 40/94 interchange: Take Highway 94 South approximately 5 miles. The trailhead parking lot will be on your right hand side. It is not very well identified as "Lost Valley". A good landmark is the shooting range at the top of a hill on the right hand side of Hwy 94. When you descend that hill the parking lot will be on your right hand side, at the very bottom. It can also be accessed by going 7.2 miles east on the Katy Trail from Klondike Park.

Trail Information




10.5 miles




Trail Conditions

Latest Conditions

From Turk1985 on Thu, 03/21/2019 - 3:30pm - Lost Valley (St. Charles Area)
Good to go, only a few wet spots remaining to ride around. One tree still down on lower two track.
From Dogface on Sun, 03/17/2019 - 8:28pm - Lost Valley (St. Charles Area)
Trail is about 75% dry. There is some spots that are still holding water. Two trees down. One on the tops in the single track and the other on the double track. Should improve throughout the week.
From soberstormtrooper on Sun, 03/03/2019 - 10:33pm - Lost Valley (St. Charles Area)
As long as it is below freezing AND before 11am or after dark the trail is good to go!
From soberstormtrooper on Sat, 02/09/2019 - 1:51pm - Lost Valley (St. Charles Area)
people rode this trial when musho soft leaving slices/ruts/damage. Ground has never been more saturated. It’s rideable when frozen and before the sun hits it (11am ish) (or after it re freezes at night) otherwise stay off please!
From STLYelli on Sun, 01/27/2019 - 10:13am - Lost Valley (St. Charles Area)
Nice and frozen at 11. Two trees down and one hanging over trail.
From WeekendRider on Sun, 01/20/2019 - 3:52pm - Lost Valley (St. Charles Area)
Ground is frozen with ice on some rock surface might need to hike your bike for safety.