Foresthill, CA (outside of Sacramento)

Avg Temps f.

69/44 (much hotter in the canyons)

Gain/Loss in ft

25k: 3500/3500

100k: 15k/15k

ft/mile gain

25k: 226ft/mile

100k: 242

Highest Elev.

~4400 ft


25k: 7:00am

100k: 5:30am


Single track trail

Time Limit

25k: None

100k: 18 hours



Furthest Aid

7.3 miles (2x)


Quick Summary: The Canyons 100K is a double out-and-back course based in Foresthill CA with a start-finish-village at the old Foresthill Elementary School. It is run mostly on single-track, on the historical Western States Trail, running scenic and challenging sections of trail along familiar WS100 course highlights like Swinging Bridge and Rucky Chuck River. The 25k is also an out and back course which doesn’t quite reach the canyons, but with 3500 feet of elevation gain, is still a challenging course on beautiful trails.

Race Details

Detailed course description – 100k:

  1. Starting out on the road from Foresthill, runners pick up single track at 1.5 miles as they drop into Volcano Canyon.
  2. Then runners have a sharp climb followed by rollers to Michigan Bluff at mile 6.2
  3. Next is a nearly 3 mile, 1800 ft drop down El Dorado Canyon at mile 9.
  4. The biggest climb of 2500 feet is next until mile 13.5.
  5. After passing by Devil’s Thumb runners will plunge down the extremely steep and twisting descent of 1700 feet in 1.5 miles to the Swinging Bridge at the turn around.
  6. Turn around and head back the same way to Foresthill.
  7. From Foresthill runners are on another short road section before getting on single track again. A steep descent and several creek crossings lead up to mile 35.5.
  8. The trail rolls until hitting a very steep “elevator shaft” descent prior to Cal2 at mile 40.5. Runners should fill up here, as it’s almost 8 miles to Rucky Chucky and the turn around at mile 47.8 in what is likely the heat of the day.
  9. Cal Street to Rucky Chucky is the fastest 16-mile section of the WS Trail, but runners need to save energy for the climb back to the finish after turning around at Rucky Chucky.

Lessons Learned from Race Reports

  • It gets very hot in the canyons and as the day progresses, especially on the long sections without aid
  • Use the creek crossings and the river to cool off
  • Take advantage of the sponges with cold water at the aid stations to cool off
  • The first 50k has more, steeper climbs and more technical terrain than the second 50k (and has 9,000 feet of gain vs. 5000 in the second half)
  • First creek crossing is in the dark
  • Quads tend to get beat up by the downhills in the first half of the race
  • Tough climbing in the darkness once the sun sets
  • Poison oak on the course
  • Trekking poles can be really helpful in the first half of the race
  • Weather is typically hot but also need to be ready for cool and rainy, which could drastically change gear and nutrition choices along the way
  • Climbing feels relentless throughout the entire day
  • Train for being able to hike and climb, and then switch right back into running gear for flats and downs, and smaller inclines
  • Train with fully loaded pack and bottles.  When you come out of an aid station with two full bottles and ice in your pack, you feel really weighed down.
  • Save enough energy for the second half of the course, as it has some more runnable sections than the first


Total gain/loss: (25k) 3,500/3,500 and (100k) 15,000/15,000

Total climbs: 25k has 1×750, 1×1500, and countless rollers




Countless rollers and 100-500 ft gains

25k: Maps/Elevation

100k: Maps/Elevation

Aid stations

25k: 2 aid stations at miles 3.1 (water only) and 8 (gels, chews, electrolytes)


Total aid stations: 12

Furthest distance apart: 7.3 (twice)

Locations: 6.2, 9, 13.5, 18.5, 23, 25.8, 32, 35.5, 40.5, 47.8, 55.1, 60.1

What’s available: Ultrarunner favorites including GU gels and chews, Gu Roctane Summit Tea energy drink, water, Trail Butter, PB&J sandwiches, Coke, Sprite, fresh fruit, potatoes, and salty & sweet snacks. If it’s a hot day, it can get very hot in the canyons, and the race recommends that you carry a minimum of 2 water bottles or a hydration pack.

Crew access

Allowed at Foresthill, which is the start, finish, and the halfway point (miles 0, 32, and 63.6), and at Rucky Chucky (47.8). There is a day-use fee collected by State Parks at Rucky Chucky. The road down to Rucky Chucky is steep, rocky, and a bit dicey for smaller cars, so you may not want to make the trip down there, as it’s not for the fainthearted or for the less agile car.


25k: None

100k: Runners leaving Rucky Chucky (mile 47.8) after 6pm may have a safety runner.

Race Qualifiers

UTMB – 5 points

Western States (finish under 18 hours)

Race reports

Jeff K’s 2019 100k Race Report

Jeff K’s 2017 100k Race Report

Strava activities and GPX files

Race Website