Phase One of the Boulder Velodrome Mountain Bike Park is complete, as shown above, which provides kids and beginners somewhere to practice their skills. Work continues on expanding the more technical mountain bike sections to go inside the velodrome, and a planned map of “trails” is shown after the break.  Looks cool, and I’m sure it’s expensive to build and maintain, but it the experience comes at a cost…the daily ($9-$19), weekly ($69-$85), monthly ($99-$149) and annual ($450) passes are pretty expensive in my opinion (price varies based on season).
The Blue and Green are the beginner/kids sections.  The Red and Yellow are the more advanced sections that are planned.  They offer classes, clinics and summer camps, too.
Pic at top from 303cycling.com, which covers Boulder, CO, area cycling news and events.
