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
Log in
Sign up

Tamalpa Headlands 50K Muir Beach, California, United States

Name: Tamalpa Headlands 50K
Start: 2024-08-17
End: 2024-08-17

Find race
Tamalpa Headlands 50K

Course maps

Download GPX Email GPX Export to Garmin

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.)

Embed Edit race

Edit POIs

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 | 17 Aug 2024 | 7:30 am

30.4 mi

Distance

Elevation gain

1,565 ft

Elevation high

607 ft

Elevation avg

Trail/Dirt

Elevation loss

0 ft

Elevation low

23%

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 23% over 30.4 mi, which means that the energy expenditure for the run is equivalent to running a flat 37.3 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 7 May 2017

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 2024.

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

Subscribe to HelloDrifter

Select subscription type

Pro

Embed & share WebGL maps for your events.

Starts at $7/mo.

Basic

Create & view WebGL maps for personal use.

Surface detail information for this course is unavailable.Learn more.

Surface detail information

HelloDrifter takes a few minutes to obtain surface detail information for every course created on the site. When present, clicking the "information" icon on the right of the map will cause sections of the course to display whether they are path, road, gravel, or dirt.

Please note that this feature is not available everywhere in the world (yet). We currenly support North America, Australia, and Europe. Even then, surface details aren't available unless the course matches data that is available in OpenStreetMap. (Typically, this means that we can't get surface details for very remote courses or courses with imprecise GPX data.)

If you have any questions, contact us through the link at the bottom of the page.