Betasso Preserve is just outside of Boulder West Canyon Road/119. Betasso has two main trail loops, Canyon and Benjamin, with one connector in the middle from the main parking lot. There is also two trail connector trail links. One connector is right off Canyon Road(right before the tunnel) which lead to Canyon Loop. The other Connector is off 4 Mile Canyon Road which leads to Benjamin Loop. If you ride both connectors and the main loops you will end up riding 11 miles with about 2000 ft of climbing. Betasso is closed to bikers on Wednesdays and Saturdays. To get to the main parking lot, go up Canyon Rd (119), Right onto Sugarloaf Rd and a Right onto Betasso Rd.
Betasso is mostly tree covered making the snow stay longer in the winter along with a nice shaded ride on hot summer days. The trail flows along the mountain side with several berms, fast down hill sections and some harder steep climbs. The trail isn't very technical, there are a few rock garden sections and a couple hard obstacles. The hardest trail is the connector trail that is right off Canyon Road. This trail is a very steep climb with several rock paths and tight switch backs. I parked at this trail head, you can also take the bike path up from Boulder which is only about 4 miles, then you you'll have the great downhill run to look forward to when your done. The trail going down is a lot of fun with large berms, a few jumps and the rock gardens to fly through.
The trail surface is dry, hard-packed dirt most of the way with softer sandy sections as well. There are some nice views along the way which looks out over the hilly terrain of the foothills. Canyon and Benjamin Loop are directional, watch for the signs to show which way bikes much go. The three connectors have two way traffic and with this trailing be so close to Boulder I can get busy. Make sure you slow down and watch out on blind turns for dogs, hikers/runners and other bikers.
Click here for a Trail Map. There is quite a bit of wild life when going through the trail. Use caution and your best judgements. Respect the trail, please keep of trails when there too wet.