This calendar was correct as of February 4th, 2015. Some races will get cancelled or change dates, so please check this information carefully. More races will be added when the dates are known.
| Date | Name | Location | Discipline | Series/Promotor | Website |
| Saturday, 14 March 2015 | Bonelli US Cup #1 | San Dimas, CA | XC | USA Cycling ProXCT Series | http://www.usacycling.org/2015-pro-xct-calendar-includes-expanded-and-enhanced-us-cup-pro-series.htm |
| Saturday, 14 March 2015 | True Grit Epic | St. George, UT | Marathon | National Ultra Endurance Series | http://nuemtb.com/series/series-calendar |
| Saturday, 21 March 2015 | Fontana US Cup | Fontana, CA | XC | USA Cycling ProXCT Series | http://www.usacycling.org/2015-pro-xct-calendar-includes-expanded-and-enhanced-us-cup-pro-series.htm |
| Saturday, 28 March 2015 | Austin Rattler | Austin, TX | Marathon | Leadville series | http://www.leadvilleraceseries.com/ |
| Saturday, 11 April 2015 | Bonelli US Cup #2 | San Dimas, CA | XC | USA Cycling ProXCT Series | http://www.usacycling.org/2015-pro-xct-calendar-includes-expanded-and-enhanced-us-cup-pro-series.htm |
| Saturday, 18 April 2015 | Sea Otter Classic | Monterey, CA | XC | USA Cycling ProXCT Series | http://www.usacycling.org/2015-pro-xct-calendar-includes-expanded-and-enhanced-us-cup-pro-series.htm |
| Sunday, 19 April 2015 | Rumble at 18 road | Fruita, CO | XC | http://www.madracingcolorado.com/ | |
| Friday, 24 April 2015 | Whiskey Off Road | Prescott, AZ | Marathon | Epic Rides | http://www.epicrides.com/index.php?contentCat=6 |
| Saturday, 25 April 2015 | Ridgeline Rampage | Castle Rock, CO | Marathon | Rocky Mountain Endurance Series | http://www.warriorscycling.com/races/ |
| Saturday, 25 April 2015 | Cohutta 100 | Ducktown, TN | Marathon | National Ultra Endurance Series | http://nuemtb.com/series/series-calendar |
| Friday, 1 May 2015 | 18 hours of Fruita | Fruita, CO | Marathon | http://18hrsoffruita.com/ | |
| Saturday, 2 May 2015 | US Marathon National Championships | Columbia Couty, GA | XC | National Championships | http://www.usacycling.org/2015/marathon-mountain-bike-nationals |
| Friday, 8 May 2015 | Nordic Valley stage race | Ogden, UT | Stage race | USA Cycling ProXCT Series | http://www.usacycling.org/2015-pro-xct-calendar-includes-expanded-and-enhanced-us-cup-pro-series.htm |
| Saturday, 9 May 2015 | Battle the Bear | Morrison, CO | Marathon | Rocky Mountain Endurance Series | http://www.warriorscycling.com/races/ |
| Saturday, 9 May 2015 | 12 hours of Mesa Verde | Cortez, CO | Marathon | http://www.12hoursofmesaverde.com/ | |
| Saturday, 16 May 2015 | Gunny Enduro | Fruita, CO | Enduro | http://www.madracingcolorado.com/ | |
| Saturday, 16 May 2015 | Pisgah 111k | Pisgah National Forest, NC | Marathon | Pisgah Productions, LLC | http://www.pisgahproductions.com/events/pisgah-111k/about/ |
| Saturday, 16 May 2015 | MTN View Epic | Mountain View, AR | Marathon | Epic Ozark Events | http://www.mountainviewepic.com/ |
| Saturday, 23 May 2015 | Gunnison Half Growler | Gunnison, CO | Marathon | http://gunnisontrails.com/gunnison-trails-events/the-original-growler/ | |
| Sunday, 24 May 2015 | Iron Horse Classic MTB | Durango, CO | XC | http://ironhorsebicycleclassic.com/Events | |
| Sunday, 24 May 2015 | Gunnison Growler | Gunnison, CO | Marathon | http://gunnisontrails.com/gunnison-trails-events/the-original-growler/ | |
| Friday, 29 May 2015 | Grand Junction Offroad | Grand Junction, CO | Marathon | Epic Rides | http://www.epicrides.com/index.php?contentCat=9 |
| Saturday, 30 May 2015 | PV Cycle Derby | Elbert, CO | Marathon | Rocky Mountain Endurance Series | http://www.warriorscycling.com/races/ |
| Saturday, 30 May 2015 | Mohican 100 | Loudonville, OH | Marathon | National Ultra Endurance Series | http://nuemtb.com/series/series-calendar |
| Sunday, 31 May 2015 | Gowdy Grinder | Curt Gowdy State Park, WY | XC | http://gowdygrinder.com/index.php | |
| Wednesday, 3 June 2015 | Ascent Cycling Series – Palmer Park | Colorado Springs, CO | XC | Sand Creek Sports | http://www.sandcreeksports.com/ |
| Saturday, 6 June 2015 | GoPro Games | Vail, CO | XC | Vail Valley Foundation | http://www.mountaingames.com/summer |
| Sunday, 7 June 2015 | Wilmington Whiteface MTB | Wilmington, NY | XC | Leadville series | http://www.leadvilleraceseries.com/ |
| Saturday, 13 June 2015 | Winter Park Hill Climb | Winter Park, CO | XC | Epic Singletrack Series – Winter Park | http://www.epicsingletrack.com/ |
| Saturday, 13 June 2015 | The captain Enduro | Colorado Springs, CO | Enduro | http://www.captainrace.com/ | |
| Sunday, 14 June 2015 | Beti Bike bash | Morrison, CO | XC | http://www.betibikebash.com/ | |
| Wednesday, 17 June 2015 | Ascent Cycling Series – Bear Creek Terrace | Colorado Springs, CO | XC | Sand Creek Sports | http://www.sandcreeksports.com/ |
| Saturday, 20 June 2015 | Missoula ProXCT | Missoula, MT | XC | USA Cycling ProXCT Series | http://www.usacycling.org/2015-pro-xct-calendar-includes-expanded-and-enhanced-us-cup-pro-series.htm |
| Saturday, 20 June 2015 | Bailey Hundo | Bailey, CO | Marathon | http://www.bailey100.com/ | |
| Saturday, 20 June 2015 | Hundito | Bailey, CO | Marathon | http://www.bailey100.com/ | |
| Saturday, 20 June 2015 | Lumberjack 100 | Wellston, MI | Marathon | National Ultra Endurance Series | http://nuemtb.com/series/series-calendar |
| Saturday, 27 June 2015 | Winter park race 2 | Winter Park, CO | XC | Epic Singletrack Series – Winter Park | http://www.epicsingletrack.com/ |
| Saturday, 27 June 2015 | Colorado Springs ProXCT | Colorado Springs, CO | XC | USA Cycling ProXCT Series | http://www.usacycling.org/2015-pro-xct-calendar-includes-expanded-and-enhanced-us-cup-pro-series.htm |
| Saturday, 27 June 2015 | 40 in the Fort | Fort Collins, CO | Marathon | http://www.overlandmtb.org/2015-40-in-the-Fort | |
| Saturday, 27 June 2015 | Big Mountain Enduro | Snowmass, CO | Enduro | Big Mountain Enduro | http://www.bigmountainenduro.com/schedule |
| Saturday, 27 June 2015 | Fire Road | Cedar City, UT | Marathon | Leadville series | http://www.leadvilleraceseries.com/ |
| Saturday, 27 June 2015 | Wildcat 100 | New Paltz, NY | Wildcat Epic Events | https://www.facebook.com/pages/Wildcat-Epic-Events/119249454822081 | |
| Sunday, 28 June 2015 | Fat TIre 40 | Crested Butte, CO | Marathon | http://cbbikeweek.com/schedule/ | |
| Saturday, 4 July 2015 | Firecracker 50 | Breckenridge, CO | Marathon | Maverick Sports | http://www.mavsports.com/events/?event-categories=firecracker-50 |
| Saturday, 4 July 2015 | Patapsco 100 | Woodlawn, Maryland | Adventures for the cure | https://www.facebook.com/pages/Patapsco-100/494749527250497 | |
| Wednesday, 8 July 2015 | Ascent Cycling Series – CMSP | Colorado Springs, CO | XC | Sand Creek Sports | http://www.sandcreeksports.com/ |
| Saturday, 11 July 2015 | Winter Park race 3 | Winter Park, CO | XC | Epic Singletrack Series – Winter Park | http://www.epicsingletrack.com/ |
| Saturday, 11 July 2015 | Boston Rebellion ProXCT | Walpole, MA | XC | USA Cycling ProXCT Series | http://www.usacycling.org/2015-pro-xct-calendar-includes-expanded-and-enhanced-us-cup-pro-series.htm |
| Saturday, 11 July 2015 | silverrush MTB | Leadville, CO | XC | Leadville series | http://www.leadvilleraceseries.com/ |
| Saturday, 11 July 2015 | Tatanka 100 | Sturgis, SD | Marathon | National Ultra Endurance Series | http://nuemtb.com/series/series-calendar |
| Sunday, 12 July 2015 | Big Mountain Enduro | Keystone, CO | Enduro | Big Mountain Enduro | http://www.bigmountainenduro.com/schedule |
| Sunday, 12 July 2015 | Crested Butte Classic | Crested Butte, CO | XC | Colorado Endurance Series | https://coloradoes.wordpress.com/swes-event-list/cb-100/ |
| Wednesday, 15 July 2015 | US National Championships – XC | Mammoth Mountain, CA | National Championships | http://www.usacycling.org/2015/mountain-bike-nationals | |
| Saturday, 18 July 2015 | Breckenridge 100 | Breckenridge, CO | Marathon | Rocky Mountain Endurance Series | http://www.warriorscycling.com/races/ |
| Saturday, 18 July 2015 | Tahoe Trail | Truckee, CA | Marathon | Leadville series | http://www.leadvilleraceseries.com/ |
| Saturday, 18 July 2015 | High Cascades 100 | Bend, OR | Marathon | National Ultra Endurance Series | http://nuemtb.com/series/series-calendar |
| Sunday, 19 July 2015 | Ascent Cycling Series – | Colorado Springs, CO | XC | Sand Creek Sports | http://www.sandcreeksports.com/ |
| Saturday, 25 July 2015 | Colorado Epic XC | Winter Park, CO | XC | Epic Singletrack Series – Winter Park | http://www.epicsingletrack.com/ |
| Saturday, 25 July 2015 | WORCS Cup | Portage, WI | XC | USA Cycling ProXCT Series | http://www.usacycling.org/2015-pro-xct-calendar-includes-expanded-and-enhanced-us-cup-pro-series.htm |
| Saturday, 25 July 2015 | Wilderness 101 | State College, PA | Marathon | National Ultra Endurance Series | http://nuemtb.com/series/series-calendar |
| Saturday, 25 July 2015 | Big Bear Grizzly 100 | Big Bear, CA | Marathon | National Ultra Endurance Series | http://nuemtb.com/series/series-calendar |
| Saturday, 25 July 2015 | Telluride 100 | Telluride, CO | XC | http://telluride100.com/ | |
| Wednesday, 29 July 2015 | Ascent Cycling Series – Palmer Park | Colorado Springs, CO | XC | Sand Creek Sports | http://www.sandcreeksports.com/ |
| Friday, 31 July 2015 | Big Mountain Enduro | Crested Butte, CO | Enduro | Big Mountain Enduro | http://www.bigmountainenduro.com/schedule |
| Saturday, 1 August 2015 | Laramie Enduro | Laramie, WY | Marathon | http://laramieenduro.org/ | |
| Saturday, 1 August 2015 | Power of Four | Aspen, CO | XC | http://www.aspensnowmass.com/events-and-activities/events/power-of-four-mountain-bike-race | |
| Saturday, 8 August 2015 | Winter Park race 5 | Winter Park, CO | XC | Epic Singletrack Series – Winter Park | http://www.epicsingletrack.com/ |
| Sunday, 9 August 2015 | Breck Epic Stage race | Breckenridge, CO | Stage race | http://breckepic.com/ | |
| Saturday, 15 August 2015 | Leadville 100 | Leadville, CO | Marathon | Leadville series | http://www.leadvilleraceseries.com/ |
| Saturday, 15 August 2015 | Pierre’s Hole 100 | Alta, WY | Marathon | National Ultra Endurance Series | http://nuemtb.com/series/series-calendar |
| Sunday, 16 August 2015 | Hampshire 100 | Greenfield, NH | Marathon | National Ultra Endurance Series | http://nuemtb.com/series/series-calendar |
| Saturday, 22 August 2015 | King of the Rockies | Winter Park, CO | XC | Epic Singletrack Series – Winter Park | http://www.epicsingletrack.com/ |
| Saturday, 22 August 2015 | Rincon Challenge | Liberia, Costa Rica | Marathon | National Ultra Endurance Series | http://nuemtb.com/series/series-calendar |
| Saturday, 29 August 2015 | Barn Burner | Flagstaff, AZ | Marathon | Leadville series | http://www.leadvilleraceseries.com/ |
| Saturday, 29 August 2015 | Cougar Slayer | Nederland, CO | Marathon | https://thecougarslayer.wordpress.com/2015-registration/ | |
| Saturday, 29 August 2015 | X100 | Traverse City, MI | Marathon | X100 | http://www.x100race.com/ |
| Friday, 4 September 2015 | Big Mountain Enduro | Winter Park, CO | Enduro | Big Mountain Enduro | http://www.bigmountainenduro.com/schedule |
| Saturday, 5 September 2015 | Park City Point to Point | Park City, UT | XC | http://thepcpp.com/race/race-registration/ | |
| Sunday, 6 September 2015 | Dakota 5 0 | Spearfish SD | Marathon | http://www.dakotafiveo.com/ | |
| Sunday, 6 September 2015 | Shenandoah 100 | Harrisonburg, VA | Marathon | National Ultra Endurance Series | http://nuemtb.com/series/series-calendar |
| Saturday, 12 September 2015 | Vapor Trail 125 | Salida, CO | Marathon | http://www.vaportrail125.com/ | |
| Saturday, 12 September 2015 | Winter Park Epic 50 | Winter Park, CO | XC | Epic Singletrack Series – Winter Park | http://www.epicsingletrack.com/Epic50.html |
| Sunday, 13 September 2015 | The Fall Classic | Breckenridge, CO | XC | Maverick Sports Promotions | http://www.mavsports.com/events/?event-categories=fall-classic |
| Saturday, 19 September 2015 | Banana Belt | Salida, CO | XC | http://bananabeltloop.com/ | |
| Saturday, 19 September 2015 | Fool’s Gold 100 | Dahlonega, GA | Marathon | National Ultra Endurance Series | http://nuemtb.com/series/series-calendar |
| Tuesday, 22 September 2015 | Steamboat Stinger | Steamboat Springs, CO | XC | www.honeystinger.com/steamboatstinger.html | |
| Sunday, 25 October 2015 | US Collegiate Mountain Bike Nationals | Snowshoe Mountain, WV | XC | National Championships | http://www.usacycling.org/2015/collegiate-mtb-nationals |