Create Race Event or a Route?

Not sure which to choose? Read this. Creating a race event allows you to group together multiple courses under a single event and provides additional features when embedding. Routes on the other hand are convenient for simpler circumstances.

Find race
Pricing
Log in
Sign up

Find a race

Advanced search filter

You need to sign in or sign up before continuing.

Thunder River Cascade Locks, Oregon, United States

Name: Thunder River
Start: 2026-10-31
End: 2026-10-31

Find race
Thunder River

Course maps

Download GPX Email GPX Export to Garmin Export to Wahoo

You must be a user to perform this action

The action you requested requires that you be signed in. If you don't have an account, signing up is easy, just click the "Sign up" button below. And we don't do anything creepy like sell your data or spam you to oblivion with nonsense. (We hate that stuff too.)

Before you continue

HelloDrifter does not warrant the accuracy of this course data; it is provided for informational use only. Verify the course against the event organizer's published materials before relying on it for navigation or safety-critical activities.

Heads up: this course is not currently managed by a race director. Check with the event organizer for any last-minute changes before you rely on it.

By continuing, you accept the site's terms and conditions.

Embed

Edit the course Edit POIs Course cuesbeta

Route source

You must be a user to perform this action

Access to our embedded maps features is reserved for our users. Plese sign in or sign up using one of the links below.

Foot race | 31 Oct 2026

15.4 mi

Distance

Elevation gain

981 ft

Elevation high

512 ft

Elevation avg

Trail/Dirt

Elevation loss

79 ft

Elevation low

13%

Climb factor

What is climb factor?

The climb factor for a course is the percentage of your energy used in hill-climbing compared to the energy expended running the flats.

This course has a climb factor of 13% over 15.4 mi, which means that the energy expenditure for the run is equivalent to running a flat 17.4 mi.

Climb factor is provided courtesy of Ben Crowell, who both authored climb factor's scientific paper and wrote the open source software for it. You can read more about it here .

Course last updated 10 Nov 2025

All values approximate

Distance & elevation data

The distance or elevation data not precisely what you expect for this route?

Data from a GPS device can be rough, especially in areas where the terrain (trees, canyons) interfere with GPS signals. And routes drawn on our maps are reliant on people marking trails from satellite images -- the details of which can be hidden by trees.

Elevation can be tricky too. Elevation data is stored on spaced topographical lines, and determining the elevation of a point requires computers to estimate based on how close the point is to the topographical line.

We mitigate this by calculating distance in 3-D (think Pythagorean theorem) and using mathematical techiniques to smooth the elevation data. We come close, but no one can be perfect with imperfect data, even in 2026.

Subscribe to build and embed our maps for personal or commercial use.View plans.