Marshall Mesa: Easy terrain with breathtaking views of the Flatirons. Suitable for everyone, but best for first-time riders in the front range.
Betasso Preserve: Betasso is one of the Boulder Mountain biking staples. For the most part the trails are very fast and flowy with a couple technical sections thrown in for good measure. Most of Betasso is suitable for beginner to intermediate riders and yet will also bring a grin to the most experienced riders.
Heil Ranch: One of the more technical intermediate trails in the Boulder area. The trail itself is not difficult however the rocks covering it pose a bit of a technical puzzle.
Walker Ranch: Nestled behind the Flatirons Walker ranch has a little bit of everything, from smooth loamy descents to rocky uphills. This trail will challenge you in both aerobic and technical ability. Don't worry though, the views and scenery are well worth it!
Valmont Bike Park: Valmont is the local dirt jump park here in Boulder. If that's not your thing don't count it out, there is a little bit of everything to keep everyone happy. This also happens to be where the 2014 Cyclocross National Championships were held.
West Magnolia: This is a staple in the Nederland Mountain bike scene. Being in the "High Country" you get a little bit of everything from aspen groves to big clearings with rock features. If you can only do one ride in Nederland this is the one.
East Magnolia: The East Magnolia trails are of the same "flavor" as the West Magnolia trails. They're just on the other side of the road, thus deserve their own name...or so that seems to be the logic. Riding both East and West Magnolia is a great way to get a solid day of singletrack in!
Sourdough: Sourdough is one of the more technical trails in the Nederland area. Don't be fooled by the distance, this is not as short of a ride as you would think. For a big day combine this with South St. Vrain.
South St. Vrain: South St. Vrain is very similar to the Sourdough trail. Be ready for big gnarly rock gardens and some digging into the trials tool bag to see what you can clear and what you can't. A great ride for mid summer when the fitness and skills are top notch!
Hall Ranch: This trail system has a little bit of everything for everyone. From big technical rock gardens to smooth flowy trails in prairies this is a must do ride in the area.
Picture Rock: Picture rock is the trail that connects Lyon's to the Heil Ranch trail system. The bottom is very smooth and gradual, the higher you go though the rockier it gets. Definitely a great ride for just about anyone that feels comfortable on a Mountain bike.