Big Sur and the Ventana Wilderness region is some of the most difficult wilderness terrain in the country. California’s fire seasons and intense winter storm change the trail network and trail conditions annually. The trail network at any given time is a mix of maintained trails, overgrown social paths, official reroutes, and segments that have simply stopped existing.
I’ve been hiking in Big Sur for over a decade and have run into all sorts of trail conditions, from beautifully pristine trail to crawling through poison oak on my hands and knees.
California’s true “Pacific *Coast* Trail”, the Condor Trail, runs beautifully through this region.
BigSurTrailMap.net
For over a decade, Jack Glendening has maintained BigSurTrailMap.net, the best resource available to monitor trail conditions for the entire Big Sur trail network. It’s updated regularly after storms and fire events, color-codes every trail segment by current passability, and is my first stop before planning a backpacking trip through Ventana.
The problem for Gaia GPS, and other GPS users, don’t really have an option to use this trail condition resource in the backcountry.
The files that Jack provides don’t maintain trail condition color coding if you download the data and get it on your device.
Jack has also set up a tile server for campsites and streams, which is worth enabling separately. Setup instructions are on his site.
The Color-Coded GPX
I wrote a Python script that runs every Sunday on my server. It downloads the latest KMZ from BigSurTrailMap.net, parses the KML inside it to extract trail coordinates and condition codes, and converts those codes to Gaia GPS’s GPX color extension format. The result is a GPX file with around 520 track segments, each color-coded to match the current trail condition.
The color mapping in Gaia:
| Color in Gaia | Condition |
|---|---|
| 🟢 Green | Good — open and passable |
| 🟡 Yellow | Use caution — some issues, route requires attention |
| 🟠 Orange | Difficult — significant route problems, passable with effort |
| 🔴 Red | Impassable — do not attempt |
| 🟣 Purple | Excellent condition |
| ⬛ Black | Unknown / abandoned / route lost |
Download the GPX
The file below is updated every Sunday. If you’re planning a trip more than a week out, re-download it closer to your start date.
How to Import Into Gaia GPS
The import process works through the Gaia GPS website — you can’t do this from the mobile app directly.
- Download the GPX file above to your computer
- Go to gaiagps.com and log in
- Click Import in the left sidebar and select the downloaded GPX file
- Gaia will create a folder containing ~520 tracks, one per trail segment
- Open the Gaia GPS app on your phone — the tracks will sync automatically
- In the app, toggle the folder on or off as a layer from your track list
Set the track opacity to around 70% so the condition colors are visible over whatever base map you’re using. The color-coded trails overlay cleanly on both the USFS topo and satellite imagery.
Updating When Conditions Change
When trail conditions update significantly — after a major storm or fire event — re-download the GPX and replace the folder in Gaia:
- In the Gaia GPS app or website, find the existing Big Sur trail folder and delete it
- Download the new GPX from the link above
- Import it following the same steps as the initial setup
The Sunday update cadence means the file generally reflects conditions from within the past week. In rapidly changing conditions (active fire season, post-storm), check BigSurTrailMap.net directly for the most current information before relying on the GPX.
A Word of Caution
In February 2024, a bug in the color-coding logic marked “lost” trails with the wrong condition code. I used the file for a Big Sur trip and ended up doing several hours of unsafe bushwhacking in terrain that the GPX had indicated was passable. That bug has been fixed, but the point stands: this is a derived data source. The colors reflect what BigSurTrailMap.net reported at the time of the last Sunday update, processed through a script that could have errors.
Before any serious trip into the Ventana, check BigSurTrailMap.net directly and compare the current state of the site with what the GPX is showing you. If there’s a discrepancy, trust the source.
Contact me if you find errors or the GPX stops updating.