ExtremeJuly

Hardrock Hundred Endurance Run

Silverton, Colorado
100.5 miles

The most difficult 100-miler in America. A clockwise or counter-clockwise loop through the San Juan Mountains with 13 major climbs, five passes above 13,000ft, and an average elevation of 11,186ft.

Race Overview

Distance
100.5 miles
Cutoff Time
48 hours
Finish Rate
65-75%
Entrants
~140
Terrain
Trail
Month
July

Terrain

Extreme alpine terrain with steep climbs, technical descents, snow fields, and exposed ridges above treeline

Entry Method

Lottery with strict qualifying standards (must finish a Hardrock qualifier)

Elevation Profile

Start: 9,318ft
High: 14,048ft
Elevation Gain

33,050 feet

Elevation Loss

33,050 feet

High Point

14,048ft

Low Point

7,680ft

Elevation Range: 6,368 feet

Key Course Sections

Silverton to Telluride

Extreme
Miles 0-28+11,600 / -10,900 feet

First major test with KT and Virginius Pass. Some of the most beautiful and brutal terrain.

Telluride to Ouray

Extreme
Miles 28-44+6,700 / -7,400 feet

Oscar's Pass and Engineer Pass. High alpine exposure with significant altitude.

Ouray to Grouse Gulch

Extreme
Miles 44-58+5,750 / -5,400 feet

Midnight climb of Grant Swamp Pass. Night navigation in extreme terrain.

Grouse Gulch to Chapman

Extreme
Miles 58-75+5,900 / -6,250 feet

Handies Peak (14,048ft) is the highest point. Oxygen is thin, view is unbelievable.

Chapman to Finish

Extreme
Miles 75-100.5+5,600 / -5,600 feet

Final climbs and descents back to Silverton. No easy miles in Hardrock.

Recommended Pacing Strategy

Hardrock isn't about pace—it's about survival and forward progress. Power hiking is the primary mode of movement. The goal is to keep moving consistently, eating regularly, and not making mistakes that lead to DNF. Most finishers hike 70-80% of the course.

Key Pacing Tips

  • Accept that you'll hike most of the race - make peace with it
  • Navigation skills are essential - GPS and map required
  • Don't count on running much above 12,000ft
  • Weather can change in minutes - always carry gear
  • This race is about experience and survival, not speed

Get Your Personalized Pacing Plan

Upload the Hardrock Hundred Endurance Run GPX file and receive a segment-by-segment pacing strategy tailored to your goal time, optimized for every climb and descent.

Common Challenges

  • Highest average elevation of any 100-miler (11,186ft)
  • Snow fields can persist through July
  • Lightning danger on exposed ridges
  • Extreme technical terrain requiring constant focus
  • Altitude sickness and hypoxia

Recommended Gear

  • Mandatory gear list including navigation tools
  • Microspikes or traction devices (snow likely)
  • Full weather protection (rain, wind, cold)
  • Trekking poles (absolutely essential)
  • Multiple headlamp batteries for 48hr effort

Course Location

Silverton, Colorado

37.8117, -107.6648

Silverton, ColoradoView on Google Maps →

Quick Stats

Distance100.5 miles
Elevation Gain33,050 feet
Elevation Loss33,050 feet
High Point14,048ft
DifficultyExtreme

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