Mountain Lakes 100 Race Info

Summary: One of the more scenic 100 milers in a remote area in Central Oregon (Olallie Lake), this race is mainly an out and back course with a 26 mile loop at the start and a 15 mile loop at the furthest point out. Along with featuring 60 miles of the Pacific Crest Trail, the course is a mix of singletrack (87.7 miles), jeep roads (12 miles) and pavement (.2 miles), along with a gain of ~10,800 feet. 2017 was a different course due to wildfires, so the gain was ~2,000 feet more, and at least 8 inches of recent snow made for a very challenging race.

Lessons Learned from Race Reports

  • All aid stations are cupless
  • Unlikely to have cell service at the race, so if you are meeting people or pacers and/or crew are coming, have a plan for meeting without needing cell service
  • The area in general has not much more than campsites, so come with all the supplies you need, plenty of gas and food, and give yourself enough time to drive there with really slow, pot-holed roads
  • First loop has some of the more technical trails
  • PCT miles are traditionally more runnable, but don’t expect them to be non-technical
  • Have warm layers for when the sun goes down, as it will be chilly at night
  • Roads for crew are fairly rough and tough to navigate, especially at night. Make sure your crew knows this going in.
  • Course is very well marked
  • Rocks are slick in the morning at the start and the next morning from morning dew or if it’s rained – be careful not to slip
  • Have a change of clothes in a drop bag for changeover from night to day so you stay warm with the big temperature swings
  • Likely running through the entire night, so have a backup headlamp and/or backup batteries, as it’s about 12 hours of nighttime


Total gain/loss: 10,800/10,800

Ft/mile gain: 108

Total climbs: 1×2000, 1×1700, 4×500, 3x~750-1000

Course Map / Elevation profile

Caltopo Map (loads faster than PDF course map)

Aid stations

Total aid stations: 16

Furthest distance apart: 10

Locations: Miles 5, 11, 21, 26, 30, 37, 45, 50, 55, 61, 66, 70, 75, 81, 88, 96

What’s available: Typical ultra food (i.e. chips, PBJ, fruit, cookies, crackers, candy), in addition to S-Caps, water, GU Hydration, and GU gels. There is also warm food available during the night.

Crew access

Access Locations:

Aid Station #2/Powerline (mile 11.4)
Aid Station #4/Olallie Lake (mile 26)
Aid Station #5 & 16/Olallie Meadows (mile 30 & mile 96)
Aid Station #9 & 12/Clackamas Ranger Station (mile 55 & mile 70)
Aid Station #11/Timothy Lake Dam (mile 66)

Crew instructions/directions (pdf), also on website


Allowed starting at mile 55 or 70 (Clackamas Ranger station) and runners age 60 or over are allowed a pacer starting at mile 26.

Race qualifiers

Western States 100

6 UTMB Points

Race reports

Roey P’s 2018 Race Report

Daisy C’s 2016 Race Report

Strava activities and GPX files

Race Website

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