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 sprgfd on Thu, 06/06/2019 - 4:43pm - Lost Valley (St. Charles Area)
Trail is mostly fine. The southern parking lot is open but the gravel path from that lot to the dirt trail is underwater. Park at the mound or more northern lots and use Hamburg Trail and Connector as shown on the map in order to access Lost Valley.
From bingemtbr on Wed, 06/05/2019 - 4:31pm - Lost Valley (St. Charles Area)
Trail was under 1'+ (one foot plus) of water. Never seen that before. Parked at the southern most TH. The fire road was completely underwater. Wow.
From WeekendRider on Sun, 06/02/2019 - 4:42pm - Lost Valley (St. Charles Area)
I would say yellow usual mud spot area maybe red but it doesn’t matter cuz I already seen a lot of tire tracks all over! Let it dry for 1-2 days it should be back to prestine condition again
From mleeser on Sun, 06/02/2019 - 9:26am - Lost Valley (St. Charles Area)
I’m sure it is a mess today but do not park at the main gravel lot. Can not get to the trail because of flooding. Need to park at the Mound or the other small lot right past the Mound and come in the back way. Future update would be appreciated.
From WeekendRider on Fri, 05/31/2019 - 7:06pm - Lost Valley (St. Charles Area)
From Turk1985 on Fri, 05/31/2019 - 1:05pm - Lost Valley (St. Charles Area)
Good to go. Just finishing afternoon ride.