A trail runner on a grassy ridge above a sea of clouds

American River 50 Mile Endurance Run

5 km ultra with 1,396 m of climbing that follows the American River from Folsom, California, to Auburn. Dating from 1980, it is one of the oldest 50-milers in the US.

Prepare for American River 50 Mile Run

A plan built from your answers and your race date.

trail training plan

The American River 50 runs point to point between Folsom and Auburn, California, in the Sierra Nevada foothills. The route traces the American River, beginning on fast, runnable ground along the water and turning hillier as it climbs toward Auburn. The setting is classic Northern California spring country: dry vegetation, open exposure and the chance of warm midday temperatures.

The race dates back to 1980 and stands among the oldest 50-milers in the country. It holds a fixed place on the West Coast ultra calendar and often serves as the first long goal race of the season. A single distance is offered, the 50 Mile.

The formats

One format only.

Format	Distance	Vertical gain
50 Mile	50 mi	1,396 m

When to start

At this distance, a build usually runs 12 to 24 weeks. The 2027 date is not published, so counting back from April puts the start around October 12, 2026.

These ranges are working conventions, not a research finding — no trial has compared plan lengths against each other. What matters more is that the plan was built for the weeks you actually have, rather than shrunk down from a longer one.

How to choose your start date

When to start

October 12, 2026

→ January 4, 2027

Worth reading before you enter

Races and distances Trail distances: what changes off the road Distance stops being the useful number. What decides a trail race is how long you are out, how much you climb, and how much the descents have wrecked your legs by the end. Read Training Eating and drinking: what’s proven, what isn’t This is where confident advice most often runs ahead of the evidence. Some of it is well tested. Some is opinion wearing a number. And one common habit can kill you. Read Races and distances When to start preparing your race Most plans fail before the first session, because the block started too late and everything had to be squeezed. Counting back from the date is the dullest and most useful thing you will do. Read

Questions

What is the date of American River 50 Mile Endurance Run in 2027?

The date of Saturday, April 3, 2027 is going around for American River 50 Mile Endurance Run, in Folsom, but the organizer has not confirmed it. Check their website before you commit.

What level do you need for the American River 50?

5 km with 1,396 m of climbing calls for a strong endurance base and at least one multi-hour long run on rolling trail behind you.

Is the American River 50 course hard?

Climbing is moderate for a 50-miler at 1,396 m of gain. The difficulty comes from the distance, possible April heat and the steeper terrain in the final stretch toward Auburn.

Other races

This list keeps growing; it draws no line. A race that is missing is prepared for in exactly the same way.

Honolulu · United StatesUltra HURT 100 Jan 16 Its five-loop, 20-mile-per-lap format carries a famously high drop-out rate. Bandera · United StatesUltra HOKA Bandera Endurance Trail Race January The HOKA Bandera Endurance Trail Race is a trail and ultra weekend held in Bandera, Texas, inside the Hil Moab · United StatesUltra Moab 240 Endurance Run January 7 km ultramarathon with 9,620 m of vertical gain, run as one continuous loop out of Moab, Utah. It is par Your race is not here? Tell us about your race You can prepare for it all the same. Any race, anywhere, and even a goal without a race.

Your race is on the calendar. Your plan should be too.

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