There's loads of good mountain biking trails in the Pocatello, ID area as well as Driggs, ID. As far as the rest of Idaho, its pretty sparse. There's some riding in an area called Kelly Canyon near Idaho Falls, ID.

• Southwestern Idaho Trail Maps - Dozens of hiking and biking trail in southwest Idaho in GPX format. GPX format bread crumbs are available or you can download a printable topographic map of each trail in Adobe PDF format. Dave has even written his own mapping program, Wissenbach Map3D!
• Brundage Mountain Resort
• CNN.com: "Idaho Tops States in Mountain Biking Report Card"
• Mike's Mountain Bike Page
• Mountain Biking Southwest Idaho
• Mountain Biking Trails in Idaho
• Southwest Idaho Mountain Bicycling Association
• Trailmonkey Bike Trails
• Local trails from
  dirtworld.com
  MTBR,
  Trails.com
• North Idaho Trails
• The Wild Rockies "Unplugged" Mountain Bike Racing Series
• Dan Simonson describes the Glidden Pass ride (near Burke)
• The Fisher Creek Trail (Sawtooth Mountains)
• The Sawtooth Challenge multi-sport event, near Stanley
• Ketchum/Sun Valley area: Trail 142
• The Ridge To Rivers trail system, near Boise
• Here's a good collection of North Idaho Trails:
  www.northidahotrails.net/trails.htm.
• Not a mountain bike trail, but maybe also worthy of mention here is the Trail of the Coeur d'Alenes and Hiawatha bike paths in North Idaho. For more information, check out:
  www.friendsofcdatrails.org

dirtdart.com is a Boise area mobile bike service