Butte 100 Race Information

99.8 miles; ~16,600 ft. elevation gain; 10 aid stations


Overview: The Butte 100 course consists of a figure-eight format on a “North Loop” and “South Loop,” guaranteeing racers never see the same trail twice.

Racers will begin heading north. 2012’s changes to the north loop have been met with rave reviews and this year’s course will have very minimal reroutes from 2013. The 100-mile racers will find a fast track and nearly always challenge the course record! The North Loop runs 52.2 miles and approximately 6,156 feet of climbing over mainly dual-track jeep trails. The diversity of trail environs will still be very evident; the north loop consists of dense wooded area with buff packed dirt, progressing to decomposed granite, and eventually a high altitude desert environment slogging through heavy sand at times. The first portion of the race will test nearly every facet of pure mountain bike skill.

After crossing back through the Start/Finish area, 100-milers go south. The South Loop is a crowd favorite with epic amounts of single track on the Continental Divide Trail, with sweeping views of the area’s mountains, and unparalleled athletic tests such as the notorious Basin Creek climb.Stats for the south loop check in at 47.5 miles with an elevation Gain of around ~8544 ft.


Start to Aid Station #1

= 5.5 miles; +1,006 ft.; 5.5 mi. cumulative

Start_AS1~3 mile Camp Caroline climb, old gravel roads, forest turning to decomposed granite sand

100 mile race start Course coming into A.S #1 AS 1 location, riders exit  A.S. to the left

 Aid Station #1 to #2

= 7.7 miles; +1,407 ft.; 13.2 mi. cumulative

AS1_AS2-dual track, old gravel roads, transitioning from decomposed granite to packed sand

Trail between a.s. 1-2 Trail between 1-2

 Aid Station #2 to #3

= 9.3 miles; +1,352 ft.; 22.5 mi. cumulative
AS2_AS3~4 mile climb on double/single track, followed by 2 mile descent on gravel road

  • packed to loose sand

sandy trail between 2-3 

 Aid Station #3 to #4

= 11.0 miles; +1,665 ft.; 33.5 mi. cumulative
AS3_AS4epic 3 mile single track descent, quite sandy high altitude desert conditions

 sandy road Between 3-4

 Aid Station #4 to #5

= 7.7 miles; +1,686 ft.; 41.2 mi. cumulative


  • notorious decent to gully crossing after railroad bed
  • ~ 5.5 mile climb to Aid Station

Out of AS #4 pipestone  trail conditions around #4 #1-#5 Aid Station Location aerial layout

 Aid Station #5 to #6 (Start/Finish )

= 11.0 miles; +1,599 ft.; 52.2 mi. cumulative


  • typically quite loose, sandy trail
  • Incorporated dual tracks this year
  • Riders must enter start/finish area and cross through timing chute

returning trail to start/finish area Returning to start/finish at 1/2 checkpoint

 Start/Finish #6 to #7 (Thompson Park)

= 7.7 miles; +1,563 ft.; 59.9 mi. cumulative


  • Cross through time gate in the start/finish area.
  • Decomposed granite hard pack, gravel roads, ~1 mile concrete.
  • Technical 2 mile Black Tail Descent. Great single track climb and descent across MT Hwy 2, through Thompson Park roads to the Aid Station
  • Short ride on an asphalt connection, through a housing division to Black Tail Trailhead; 3 mi. climb and 3 mile descent to Hwy 2 crossing and Thompson Park area

T-Park aid station and course layout

 Aid Station #7 to #8 (Basin Creek)

=8.8 miles; +1,192 ft.; 68.8 mi. cumulative


  • Granitic to hard pack on climb, loose dirt to sand graduating to gravel road on descent
  •  ~3 mile climb to the chimney trail landmark. ~3 mile descent from single track  to road- (watch for wash-outs) trail graduates to dual track, established double track, then gravel road into Basin Creek Aid station #8

Basin Creek Aid Station Gravel road into Basin Creek a.s.

 Aid Station #8 to #9 (Highlands)

= 10.7 miles; +2,593 ft.; 79.5 mi. cumulative


  • Sandy, loose, ugly ~6 mile Basin Creek Climb
  • Join the CDT about 4 miles in- better trail conditions, epic flowy 4 miles on arguably the best section on the course.
  • Note: a USA Cycling official will be enforcing racer cut-offs at this aid station.

basin creek climb highlands as Highlands CDT trail

 Aid Station #9 to #10 (Hwy 2)

= 11.3 miles; +1,266 ft.; 90.8 mi. cumulative


  • Endless amount of packed CDT singletrack.
  • Section of trail know locally as “the 8 miles of hell” which, by all accounts, couldn’t be more inappropriately named after last year’s USFS trail rerouting-but the name stuck
  • 3 steady climbs and descents all hovering around 8,000 feet of elevation
  • Nice long descent to the Highway 2 aid station.
  • Those pulling in after 7:00 p.m. will no be allowed to continue, no exceptions.

Limekiln junction aerial view Hwy 2- aid stn 10 single track near limekiln

 Aid Station #10 to Finish

= 9.0 miles; +1,344 ft.; 99.8 mi. cumulative


  • ~3 mile climb out of A.S.
  • ~4 miles on popular trail section, weaving through boulders and catching glimpses of Butte on the way- be aware of other trail users
  • The trail will wrap around a small rise, go through a gate, and intersect with a road/bridge over interstate. Right Turn- Only 0.3 miles to the finish line!

Racer finishing aerial graphic Trail between Hwy2 and Finish

100 Mile
Segment Miles Cumulative
Start – AS1 5.5 5.5
AS1 – AS2 7.7 13.2
AS2 – AS3 9.3 22.5
AS3 – AS4 11.0 33.5
AS4 – AS5 7.7 41.2
AS5 – AS6 11.0 52.2
AS6 – AS7 7.7 59.9
AS7 – AS8 8.8 68.8
AS8 – AS9 10.7 79.5
AS9 – AS10 11.3 90.8
AS10 – Finish 9.0 99.8

Enjoy the moment as you ride across the finish line… because you just completed the most difficult mountain bike race in the country!