While we make every attempt to ensure the accuracy of our multisport calendar, we recommend that you verify the date, time, location and distance of an event before making the journey. If you spot any errors or omissions in our race calendar, please let us know.

A Racing Underground Owned Event

A Racing Underground Timed Event

An AMB Chip Timed Event

• 1 - Falcon Groundspeed Triathlon - (0.25M Swim/15M Bike/5K Run)(1500m Swim/25M Bike/10K Run) - USAF Academy, Colorado - 8:00 a.m. - 719-333-4532

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• 5 - Cinco du Mayo - 5K Run, 20K Bike, 5K Run - Highlands Ranch, Colorado - 303-791-2500
  

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• 8 - Barkin' Dog Duathlon, Mile High Duathlon Series Race #1 - 5K Run / 30K Bike / 5K Run or 2K Run/17K Bike/5K Run - Cherry Creek State Park, Denver, Colorado - 303-642-7917
  

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• 8 - Adventure XStream Race Series - (Paddle/Mtn Bike/Trail Run) - 12 Hrs - Buena Vista, Colorado - 970-259-7771
• 8 - Tri For Me - (500m pool Swim/12M Bike/2M Run) - Montclair Recreation Center - Denver, Colorado - 720-275-0205
• 15 - Pole Pedal Paddle - (backcountry skiing, mtn bikeing, kayaking) - Monarch Pass to Salida, Colorado - 719-221-1710

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• 16 - Little Foot Triathlon - (750m Swim/20k Bike/5K Run) - Bear Creek Lake Park - Morrison, Colorado - 7:00 a.m. - 720-289-0036
  

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• 16 - Fort Collins Triathlon/Duathlon - (450Y swim/13M Bike/3M Run) - EPIC - Fort Collins, Colorado - 7:00 a.m. - 970-482-0551
• 22 - Glenwood Springs Off-Road Oyster - (run/bike/paddle/climb) - Two Rivers Park - Glenwood Springs, Colorado - 303-777-6887

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• 23 - The Summer Open Sprint Tri - (800M Swim/12.4mi Bike/5K Run) - Union Reservoir - Longmont, Colorado - 303-408-1195
  

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• 23 - Tri The Rock Youth Triathlon - (various distances) - Butterfield Park- Castle Rock, Colorado - 8:00 a.m. - 720-733-2284
• 23 - Center Beginner Triathlon - (500m Swim/13M Bike/5K Run) - Sand Dues Swimming Pool - Center, Colorado - 8:00 a.m. - 719-850-3439

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• 29 - PelicanFest Sprint Tri - (800m Swim /10M Bike/5K Run) Windsor, Colorado - 970-308-4499
  

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• 23 - Kids Triathlon - (various distances) - Buchanan Park Recreation Center - Evergreen, Colorado - 9:00 a.m. - 720-880-1219
• 30-31 - Narrow Guage Runs/Iron Horse Bike Races/1500m Swim - 3 days, 3 events - Durango, CO - 970-403-5346

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• 3 - Boulder Stroke & Stride #1 - (750m-1500m Swim/5K Run) - Boulder Reservoir - Boulder, Colorado - 6:00 p.m. - 303-642-7917
  

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• 4 - Metro Brokers Triathlon - (1/2M Swim/12M Bike/3M Run) - Cherry Creek State Park - Denver, Colorado - 6:00 p.m. - 303-843-0100
  

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• 5 - Tune Up Sprint Triathlon Adult & Kids Races - (500& pool Swim/12M Bike/5K Run)(Kids:various distances) - Westridge Recreation Center - Highlands Ranch, Colorado - 6:30 a.m. - 303-791-2500
  

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• 5 - City of Longmont Kids Triathlon - (various distances) - Centennial Pool - Longmont, Colorado - 303-774-4759
• 5 - Tri The Creek Triathlon - (800m Swim/14M Bike/5K Run) - Cherry Creek State Park - Denver, Colorado - 7:00 a.m. - 720-931-6740
• 6 - Longmont Triathlon - (525Y Swim/12MBike/5K Run) - Centennial Pool - Longmont, Colorado - 303-774-4759

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• 10 - Boulder Stroke & Stride #2 - (750m-1500m Swim/5K Run) -Boulder Reservoir - Boulder, Colorado - 6:00 p.m. - 303-642-7917
  

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• 10 - Springs Splash and Dash - (750m-1500m Swim/3.75M Run) - Kids:(200m Swim/1.25M Run) - Prospect Lake, Memorial Park - Colorado Springs, Colorado - 6:00 p.m. - 719-337-2737

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• 12 - Big Sky Duathlon, Mile High Duathlon Series Race #2 - (4K Run/25K Bike/4K Run) - Community Center - Bennett, Colorado - 8:00 a.m. - 303-642-7917
  

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• 12 - Highline Hustle Triathlon - (500m Swim/16M Bike/3M trail Run) - Highline Lake State Park - Loma, Colorado - 7:30 a.m. - 970-254-3893
• 13 - Mini Ha Ha Triathlon - (300Y Swim/11M Bike/2M Run) - Community Center - Broomfield, Colorado - 8:00 a.m. - 303-464-5500
• 15 - Dip & Dash Series - (750m or 1500m Swim/5k Run) - Aurora Reservoir - Aurora, Colorado - 6:00 p.m. - 303-359-8042

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• 17 - Boulder Stroke & Stride #3 - (750m-1500m Swim/5K Run) - Boulder Reservoir - Boulder, Colorado - 6:00 p.m. - 303-642-7917
  

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• 20 - 5430 Sprint Triathlon - (1/2M Swim/17M Bike/3.1M Run) - Boulder, Colorado - 813-868-5940
  

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• 22 - Dip, Draft & Dash - (250m Swim/8M Bike/1M Run) - Aurora Reservoir - Aurora, Colorado - 6:00 p.m. - 303-359-8042

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• 27 - SheRox Triathlon (women only) - (0.5M Swim/10M Bike/5K Run) - Aurora Reservoir - Aurora, Colorado - 7:00 a.m. - 303-882-8304
  

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• 24 - Boulder Stroke & Stride #4 - (750m-1500m Swim/5K Run) - Boulder Reservoir - Boulder, Colorado - 6:00 p.m. - 303-642-7917
  

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• 24 - Springs Splash and Dash - (750m-1500m Swim/3.75M Run) - Kids:(200m Swim/1.25M Run) - Prospect Lake, Memorial Park - Colorado Springs, Colorado - 6:00 p.m. - 719-337-2737
• 26 - Lake to Lake Triathlon - (1.5K Swim/30M bike/10K Run) - High School - Loveland, Colorado - 6:30 a.m. - 970-669-6372
• 26 - Adventure XStream Racing Series - (paddle/bike/run) - 12/24 hr - 50+ miles - Durango, Colorado - 970-259-7771
• 26 - Road Rash N' Splash Mini Triathlon - (250Y Swim/6M Bike/2M Run) - Recreation Center - Meeker, Colorado - 8:00 a.m. - 970-878-3403
• 26 - Road Rash N Splash Mini Triathlon - (250Y Swim/6M Bike/2M Run) - Recreation Center - Meeker, Colorado - 8:00 a.m. - 970-878-3403
• 27 - Craig Duathlon - (5k Run/30K Bike/5K Run) - Loudy Simpson River Park - Craig, Colorado - 8:00 a.m. - 970-824-6932
• 27 - IronKids Triathlon - (various distances) - Notthingham Park - Avon, Colorado - 9:00 a.m. - 813-868-5940
• 29 - Aquaman Swim/Run Series #1 - (0.5M-1M Swim/5K Run) - Cherry Creek State Park - Denver, Colorado - 6:15 p.m. - 303-408-1195
• 29 - Dip & Dash Series - (750m or 1500m Swim/5k Run) - Aurora Reservoir - Aurora, Colorado - 6:00 p.m. - 303-359-8042

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• 1 - Boulder Stroke & Stride #5 - (750m-1500m Swim/5K Run) - Boulder Reservoir - Boulder, Colorado - 6:00 p.m. - 303-642-7917
  

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• 1 - Springs Splash and Dash - (750m-1500m Swim/3.75M Run) - Kids:(200m Swim/1.25M Run) - Prospect Lake, Memorial Park - Colorado Springs, Colorado - 6:00 p.m. - 719-337-2737
• 6 - Aquaman Swim/Run Series #2 - (0.5M-1M Swim/5K Run) - Cherry Creek State Park - Denver, Colorado - 6:15 p.m. - 303-408-1195
• 6 - Dip, Draft & Dash - (500m Swim/10M bike/2M Run) - Aurora Reservoir - Aurora, Colorado - 6:00 p.m. - 303-359-8042

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• 8 - Boulder Stroke & Stride #6 - (750m-1500m Swim/5K Run) - Boulder Reservoir - Boulder, Colorado - 6:00 p.m. - 303-642-7917
  

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• 10 - LG Triathlon - (500m Swim/12M Bike/5K Run) - Eagle, Colorado - 970-328-9565
• 10 - Pagosa Duathlon - (6M Run/12.5M Bike)(3M Run/7M Bike)Kids-(0.5M Run/1M Bike) - Monument Park Road - 8:00 a.m. - 970-264-9075
• 10 - Pagosa Duathlon Do The Du - (6M Trial Run/11.4M Single Track Bike) - Turkey Springs - Pagosa Springs, Colorado - 8:00 a.m. - 970-264-9075

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• 11 - Boulder Peak Triathlon - (1.5K Swim/42K Bike/10K Run) - Boulder, Colorado - 813-868-5940
  

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• 12 - Dunk & Dash - *800Y Swim 1 lap or 2/5k Run) - Nottingham Park - Denver, Colorado - 720-309-7518
• 13 - Aquaman Swim/Run Series #3 - (0.5M-1M Swim/5K Run) - Cherry Creek State Park - Denver, Colorado - 6:15 p.m. - 303-408-1195
• 13 - Dip & Dash Series - (750m or 1500m Swim/5k Run) - Aurora Reservoir - Aurora, Colorado - 6:00 p.m. - 303-359-8042

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• 15 - Boulder Stroke & Stride #7 - (750m-1500m Swim/5K Run) - Boulder Reservoir - Boulder, Colorado - 6:00 p.m. - 303-642-7917
  

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• 15 - Springs Splash and Dash - (750m-1500m Swim/3.75M Run) - Kids:(200m Swim/1.25M Run) - Prospect Lake, Memorial Park - Colorado Springs, Colorado - 6:00 p.m. - 719-337-2737

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• 17 - Tri-N-July Triathlon Adult & Kids Races - (750M pool Swim/14.5 Mile Bike/4 Mile Run)(Kids: various distances) - Eastridge Recreation Center - Highlands Ranch, Colorado - 6:00 a.m. - 303-791-2500
  

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• 17 - XTERRA Beaver Creek - point to point (0.5M Swim/9M Bike/3M Run)(1M Swim/15.5M uphill Bike/5.75M Run) - Nottingham Lake - Avon, Colorado - 9:00 a.m. - 970-845-5293

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• 18 - West Side Duathlon, Mile High Duathlon Series Race #3 - (5K Run/30K Bike/5K Run or 2K Run/15K Bike/5K Run)- 7:00 a.m. - Arvada, Colorado - 303-642-7917
  

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• 18 - Tri It High Triathlon/Duathlon - (500m Swim/20K Bike/5K Run)(5K Run/20K Bike/5K Run) - Leadville, Colorado - 719-486-7484
• 19 - Dunk & Dash - (800Y Swim - 1 lap or 2/5k Run) - Nottingham Lake - Avon, Colorado - 6:00 p.m. - 970-748-4060
• 20 - Aquaman Swim/Run Series #4 - (0.5M-1M Swim/5K Run) - Cherry Creek State Park - Denver, Colorado - 6:15 p.m. - 303-408-1195
• 20 - Dip & Dash Series - (750m Swim/12M bike/3M Run) - Aurora Reservoir - Aurora, Colorado - 6:00 p.m. - 303-359-8042

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• 22 - Boulder Stroke & Stride #8 - (750m-1500m Swim/5K Run) - Boulder Reservoir - Boulder, Colorado - 6:00 p.m. - 303-642-7917
  

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• 24 - My Way or the Tri Way Triathlon - (750m Swim/14M Bike/3.5M Run) - Any Order -Aurora Reservoir - Aurora, Colorado - 7:30 a.m. - 720-934-2345
  

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• 24 - My Way or the Tri Way Duathlon - (14M Bike/3.5M Run - Choose Run/Bike/Run or Bike/Run/Bike) -Aurora Reservoir - Aurora, Colorado - 7:30 a.m. - 720-934-2345
  

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• 24 - My Way or the Tri Way Aquathlon - (750M Swim/3.5M Run - Choose Run/Swim/Run or Swim/Run/Swim) -Aurora Reservoir - Aurora, Colorado - 7:30 a.m. - 720-934-2345
  

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• 24 - My Way or the Tri Way Aquabike - (750M Swim/14M Bike - Choose Bike/Swim/Bike or Swim/Bike/Swim) -Aurora Reservoir - Aurora, Colorado - 7:30 a.m. - 720-934-2345
  

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• 24 - Loveland Sprint Triathlon - (750m Swim/13.5M Bike/4M Run) - North Lake Par - Loveland, Colorado - 7:45 a.m. - 970-669-6372
• 26 - Dunk & Dash - (800Y Swim - 1 lap or 2/5k Run) - Nottingham Lake - Avon, Colorado - 6:00 p.m. - 970-748-4060
• 27 - Aquaman Swim/Run Series #5 - (0.5M-1M Swim/5K Run) - Cherry Creek State Park - Denver, Colorado - 6:15 p.m. - 303-408-1195
• 27 - Dip & Dash Series - (750m or 1500m Swim/5k Run) - Aurora Reservoir - Aurora, Colorado - 6:00 p.m. - 303-359-8042

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• 29 - Boulder Stroke & Stride #9 - (750m-1500m Swim/5K Run) - Boulder Reservoir - Boulder, Colorado - 6:00 p.m. - 303-642-7917
  

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• 29 - Springs Splash and Dash - (750m-1500m Swim/3.75M Run) - Kids:(200m Swim/1.25M Run) - Prospect Lake, Memorial Park - Colorado Springs, Colorado - 6:00 p.m. - 719-337-2737
• 31 - State Games of America Triathlon - (750m Swim/15M bike/5K run) - Colorado Springs, Colorado - 7:15 a.m. - 719-634-7333 x1003
• 31 - Anthem Sprint Triathlon - (525m pool Swim/11.7M Bike/5K Run) - Parkside Community Center - Broomfield, CO - 7:00 a.m. - 720-270-6569

• 1 - Tri For The Cure - Womens Triathlon - (500m Swim/10M bike/5K Run) - Cherry Creek State Park - Denver, Colorado - 7:00 a.m. - 303-798-7028
• 2 - Dunk & Dash - (800Y Swim 1 lap or 2/5k Run) - Nottingham Lake - Avon, Colorado - 6:00 p.m. - 970-748-4060
• 3 - Aquaman Swim/Run Series #6 - (0.5M-1M Swim/5K Run) - Cherry Creek State Park - Denver, Colorado - 6:15 p.m. - 303-408-1195

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• 5 - Boulder Stroke & Stride #10 - (750m-1500m Swim/5K Run) - Boulder Reservoir - Boulder, Colorado - 6:00 p.m. - 303-642-7917
  

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• 7 - BEC Triathlon - (0.25M Swim/9.3M Bike/5K Run) - Nottingham Park - Avon, Colorado - 9:00 a.m. - 970-571-5544
• 7 - Aspen High Country Triathlon/Duathlon - (800Y Swim/17M bike/4M Run) - Aspen, Colorado - 970-429-2093
• 7 - Durango Parks & Rec Triathlon - (500Y Swim/13M Bike/5k Run) - Recreation Center - Durango, Colorado - 8:30 a.m. - 970-375-7306
• 7 - IronKids Triathlon - (various distances) - Boulder Reservoir - Boulder, Colorado - 813-868-5940
• 7 - Anthem Sprint Triathlon - (525m Swim/12.5M Bike/5k Run) - Parkside Community Center/Anthem Highlands - Broomfield, Colorado - 720-270-6569

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• 8 - Boulder 70.3 Long Course Triathlon - (1.2M Swim/56M Bike/13.1M Run) - Boulder, Colorado - 813-868-5940
  

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• 8 - XTERRA Indian Peaks - (1000m Swim/34K Bike/7K Run) - Eldora Mountain Resort - Nederland, Colorado - 303-279-6040
• 9 - Dunk & Dash - (800Y Swim - 1 lap or 2/5k Run) - Nottingham Lake - Avon, Colorado - 6:00 p.m. - 970-748-4060
• 12 - Springs Splash and Dash - (750m-1500m Swim/3.75M Run) - Kids:(200m Swim/1.25M Run) - Prospect Lake, Memorial Park - Colorado Springs, Colorado - 6:00 p.m. - 719-337-2737
• 14 - Durango Kids Triathlon - (various distances) - Recreation Center - Durango, Colorado - 970-375-7300

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• 14 - Rattlesnake Olympic -Distance Triathlon (1500M Swim/40K Bike/10K Run) - Aurora Reservoir - Aurora, CO - 720-232-8669
  

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• 15 - Rattlesnake Sprint Triathlon (500M Swim/12 Mile Bike/5K Run) - Aurora Reservoir - Aurora, CO - 720-232-8669
  

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• 15 - Muddy Buddy - (Mtn Bike/Run Relay) - Boulder Reservoir - Boulder, Colorado - 7:15 a.m. - 818-707-8867

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• 20 - Newton Trail Triathlon - (750M Swim/5K Run/10K Bike) - Boulder Reservoir, Boulder, Colorado - 303-857-5031
  

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• 21 - Splash-Mash-Dash Triathlon & Kids Triathlon - (1K pool Swim/31K Bike/10K Run)(Kids: various distances) - Northridge Recreation Center - Highlands Ranch, Colorado - 6:00 a.m. - 303-791-2500
  

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• 21 - PLR Kids Triathlon (various distances) - Platteville, Colorado - 970-785-2435
• 21 - Denver Oyster - (run-bike-scoot/skate-trek-climb-paddle) - Aquarium Parking Lot - Denver, Colorado - 8:00 a.m. - 303-777-6887
• 21 - Fall Frenzy Kids Triathlon - (various distances) - Grange Pool - Castle Rock, Colorado - 8:00 a.m. - 303-841-4500
• 22 - Fort Collins Kids Triathlon - (various distances) - Edora Pool - Fort Collins, Colorado - 8:00 a.m. - 970-213-2901

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• 22 - Outdoor Diva's Triathlon (Women Only) - (800M Swim/12.4mi Bike/5K Run) - Union Reservoir - Longmont, Colorado - 303-408-1195
  

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• 29 - XTERRA Lory - Lory State Park, Fort Collins, Colorado - 303-408-1195
  

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• 29 - Iron Girl Triathlon - (800m Swim/30K Bike/5K Run) - Boulder Reservoir - Boulder, Colorado - 7:00 a.m.
• 29 - Steamboat Triathlon - (3/4M Swim - 20M Bike/3.2M Run) - Lake Catamount - Steamboat Springs, Colorado - 8:00 a.m. - 970-846-8678

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• 4 - RACING UNDERGROUND 1.2Mile & 2.4Mile Open Water Swim - Boulder Reservoir - Boulder, Colorado - 6:30 a.m. - 303-642-7917
  

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• 4 - Tenderfoot Mountain Triathlon/Duathlon - (1000m Swim/40K Bike/10K Run) (40K Bike/10K Run) - Salida Hot Springs Aquatic Center - Salida, Colorado - 7:00 a.m. - 719-539-6738
• 5 - Tenderfoot Mountain Kiwanis Kids Triathlon - Kids 5-14, various distances - Salida Hot Springs Aquatic Center - Salida, Colorado - 10:00 a.m. - 719-539-6738
• 11 - Adventure XStream Race Series - (kayak/Mtn Bike/trek/ropes/navigation) - 50M/12Hr - Glenwood Springs, Colorado - 970-259-7771

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• 12 - Harvest Moon Long Course Triathlon - (1.2M Swim/56M Bike/13.1M Run) - Aurora Reservoir - Aurora, Colorado - 303-408-1195
  

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• 12 - Harvest Moon Long Course Duathlon - (5K Run/56M Bike/13.1M Run) - Aurora Reservoir - Aurora, Colorado - 303-408-1195
  

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• 12 - Harvest Moon Long Course Aquabike - (1.2M Swim/56M Bike) - Aurora Reservoir - Aurora, Colorado - 303-408-1195
  

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• 12 - TriGlenwood Triathlon - (825m Swim/15M Bike/5M Run) - Hot Springs Lodge & Pool - Glenwood Springs, Colorado - 6:30 a.m. - 970-945-2208
• 12 - Bearable Adventure Race - (Swim/run/mtn bike/orienteering) - Bear Creek Lake Park - Lakewood, Colorado - 8:30 a.m. - 720-963-5390
• 12 - Fall Frenzy Triathlon - (500Y pool Swim/13M Bike/3M Run) (3M Run/13M Bike/3M Run) - Recreation Center - Parker, Colorado - 303-841-4500
• 18 Gold Man Triathlon - (1500m Swim/24.9M Bike/6.2M Run) - Highline State Park - Loma, Colorado - 8:00 a.m. - 970-274-1232

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• 19 - Crescent Moon Sprint Triathlon - (750 Meter Swim/20K Bike/5K Run) - Cherry Creek State Park - Denver, Colorado - 303-642-7917
  

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• 26 - Oktoberfest Sprint Tri - (800M Swim/12.4mi Bike/5K Run) - Union Reservoir - Longmont, Colorado - 303-408-1195
  

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• 26 - Colorado Wild Women Duathlon - 2M Run/12M Bike/2M Run; 0.5M Run/6.5M Bike/2M Run - Aurora Reservoir - Aurora, Colorado - 303-843-9751
  

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• 2 - Black Canyon Sprint Triathlon - (500m Swim/25K Bike/5K Run)+ youth distances - Aquatic Center - Montrose, Colorado - 970-249-7705

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