International Trail Race: Western States 100 — The Holy Grail of North American 100-Milers

Introduction

The Western States 100 Mile Endurance Run (Western States 100, or WS100) is the most historic 100-mile race in the trail running world. The race originated in 1974, when Gordy Ainsleigh, whose horse was injured, completed the original 100-mile horse race course on foot, ushering in a new era of modern ultramarathon trail running. For all trail runners, WS100 is one of the most iconic trail races.

Race Basic Information

Item	Details
Distance	161K (100 miles)
Cumulative Ascent	Approx. 5,500m
Cumulative Descent	Approx. 7,000m
Cutoff Time	30 hours
Start	Olympic Valley, Squaw Valley
Finish	Auburn, California
Finisher Award	Silver Buckle (< 24h) / Bronze Buckle (24-30h)
Main Month	Late June

WS100 History and Traditions

1. Silver Buckle Tradition

The highest honor at WS100 is the Sub-24 Silver Buckle: finishing within 24 hours earns a silver buckle. The finish rate is about 60%, but the Sub-24 finish rate is only 25-30%.

2. Bronze Buckle Finisher Award

Finishing within 24-30 hours earns a bronze buckle, which remains one of the most respected finisher credentials in the trail running world.

3. Race Culture

• Race history spans over 50 years
• Approximately 380 runners finish each year
• Strict lottery-based registration
• Lifetime membership for finishers

Entry Requirements and Lottery

Qualification Requirements

To enter the WS100 lottery, you need:

1. Finish at least 1 WS100-certified “Qualifying Race” (typically a 100K+ event)
2. Finish within the past 12 months
3. Enter the lottery pool

Lottery Mechanism

WS100 uses a “weighted lottery”:

• First year in lottery: 1 ticket
• Second year without selection: 2 tickets
• Third year without selection: 4 tickets
• And so on (doubling each year)

It typically takes 3-5 years to get selected, so WS100 is not just a race—it’s a long-term commitment.

Course Analysis

The WS100 course runs from Squaw Valley to Auburn, crossing the Sierra Nevada mountain range:

Section	Distance	Main Challenges
Escarpment (0-7K)	7K	First 800m climb from the start
High Country (7-50K)	43K	High altitude 2,500-2,800m
Canyons (50-100K)	50K	Three 600m+ climbs
American River (100-130K)	30K	River crossings, river valley
No Hands Bridge (130-161K)	31K	Final climb to Auburn

Special Course Challenges

1. High Altitude

The first 50K sits at 2,500-2,800m, a severe challenge for runners not acclimatized:

• Thin oxygen
• Difficulty breathing
• Elevated heart rate
• Easy fatigue

It is recommended to arrive 5-7 days early for altitude acclimatization.

2. High Heat

In late June, temperatures in the middle section of California (canyon section) can reach 38-42°C:

• Extremely high dehydration risk
• Heatstroke cases occur every year
• Hydration needs of 1-1.5L per hour

3. River Crossings

The American River crossing is a hallmark of WS100:

• Water depth of 1-1.5m
• Strong currents
• Ropes are needed for assistance
• A challenge for body temperature management

Pacing Strategy

Tailored to WS100 characteristics:

Start Section (Escarpment)

• The first 800m climb must be hiked
• Don’t get carried away by start-line excitement
• Save energy for the high-altitude section

High-Altitude Section

• Heart rate 10-15 bpm lower than normal race pace
• Hydrate more (600-800ml per hour)
• Supplement electrolytes

Canyon Section (Most Difficult)

• High heat + continuous climbs and descents
• Full replenishment at every aid station (5-10 minutes)
• Hydration and sodium intake simultaneously

River Valley Section (Night Section)

• Entering the first night
• Temperature drops sharply near the river
• Change into dry socks and use waterproof bags before crossing

Finish Section

• Final 30K of gradual climbing
• A mental battle more than a physical one
• Calculate your time (Sub-24 or Sub-30)

Crew and Pacer Strategy

WS100 allows crews and pacers:

• Crews can meet runners at 7 designated aid stations
• Pacers can join after 100K (Foresthill)
• Crews provide supplies, clothing changes, and mental support
• Pacers run the final 60K with the runner

Training Recommendations

Key training focuses for WS100:

1. Accumulate Long Distance

In the 6 months before the race, do one 50K+ long run per week, with a total weekly mileage of 100-120K.

2. Heat Acclimatization Training

Do heat acclimatization 2-3 weeks before the race:

• Hot yoga
• Sauna sessions (20-30 minutes each)
• Running in midday heat

3. Altitude Simulation

If you live at low altitude, arrive at a high-altitude location 5-7 days before the race to acclimatize.

4. Mental Preparation

The mental battle of 100 miles:

• Write down 5 reasons you want to finish
• Imagine 3 moments of breakdown and your corresponding strategies
• Talk with runners who have finished WS100

Practical Advice

• Lottery Mindset: Treat WS100 as a long-term goal; low odds of selection in the first 2-3 years are normal
• Warm-up Races: Schedule 1-2 100K warm-up races 6 months before registering
• Gear Check: The mandatory gear list is strict, with random checks 48 hours before the race
• Insurance: Consider purchasing North American travel medical insurance (in case of injury requiring medical care)
• Jet Lag Adjustment: Taiwan is 16 hours ahead of California; arrive 5-7 days early

Conclusion

Western States 100 is not just a trail race—it is a symbol of trail running culture. From Gordy Ainsleigh in 1974 to today’s top global athletes, WS100 carries the history and spirit of trail running. If you plan to take on 100 miles, WS100 should be one of your ultimate goals. Even if you don’t get selected in the first lottery, don’t be discouraged—keep accumulating finish records and lottery tickets, and one day you will stand on the starting line at Squaw Valley.

Related Reading

• International Trail Race: Hardrock 100 — The World’s Toughest 100-Mile Race
• Bridging Trail Running and Ultramarathon Training: The Advanced Path from 50K to 100M
• Trail Race Strategy: A Finisher’s Guide to 100-Mile Races like UTMF and TNF100
• Kenting Ultra Marathon 100K: Analysis of Taiwan’s Southernmost Extreme Marathon