California National Forests

Mount Shasta Region Sample

Links to Index Maps

Sierra Nevada/South Cascade Region


Inventory Overview

This inventory tracks roadless areas greater than 1000 acres on national forest lands in California. The inventory was completed in two stages: 1) Sierra Nevada/South Cascades, and 2) Coast Ranges/Klamath Mountains. The Sierra/Cascades inventory was completed by Sierra Biodiversity Institute for the Sierra Nevada Ecosystem Project in 1995. It was published on the web in September 1998. In summer/fall 1998, with support from Patagonia, Environmental Systems Research Institute and Hewlett-Packard, Sierra Biodiversity completed the roadless area inventory for the national forests of California''s Coast Ranges and Klamath Mountains. While the analysis process is identical in these studies, the final maps are slightly different in content and layout. Before using the maps, please review the map keys for each region. We have linked to the region title in the tables above, or you can get them here: Sierra, or Coast Range.

What are Roadless Areas?

Roadless are the least disturbed, wildest and most remote regions in any landscape. Sometimes they have trails, or even jeep roads and mining cabins, but by and large they are de-facto wilderness areas. The first inventories of roadless areas, undertaken by the US Forest Service in the 1920s, laid the framework for the National Wilderness Preservation System of today. In the past few decades, wildlife and fisheries biologists and watershed specialists have discovered the biological significance of roadless areas. They are associated with the healthiest fisheries and aquatic ecosystems, with populations of many rare, threatened and endangered species, and they serve as refuges and breeding grounds for important game species like elk.

Why Re-inventory Roadless Areas?

The most recent roadless area inventory for California national forests (RARE II), was completed in 1977. Since then, the US Forest Service has build roads and logged within the boundaries of many RARE II roadless areas. Today, the RARE II inventory is badly out of date. In addition, RARE II was not a comprehensive scientific inventory. It missed many roadless lands. On the Tahoe National Forest, for example, RARE II inventoried 131,540 acres (national forest lands only). Our 1998 phase 1 inventory located 389,660 acres. During field review, we expect some of these new roadless areas to shrink in size or vanish--they may be mis-mapped. Nonetheless, our inventory mapped over one quarter of a million acres of previously uninventoried roadless land on the Tahoe National Forest alone. We estimate that nationwide 20 to 40 million acres of roadless lands may lie undiscovered and unprotected in our national forests.

Analysis Process

This roadless area inventory is based on digital road maps created by the US Forest Service. The digital data is current to the mid to late 1990''s, but on some forests may contain errors of omission or coding (ie. some roads may be coded as trails, and visa-versa). Based on detailed review by residents and conservationists, however, overall accuracy is high in the first region we mapped during the study, the Sierra Nevada/South Cascades region of northeast California. Throughout the Sierra/Cascade part of the study, accuracy is lower on private lands outside the national forest boundaries, because in these areas we used lower resolution (1:100,000 scale) digital roads data from the State of California Teale Data Center. In the Coast Ranges/Klamath Mountain part of this study, we did inventory roadless areas on private lands, except roadless private inholdings within the proclaimed boundaries of the national forests.

Using the Map Set

The roadless area map series comprises over one hundred 8.5 by 11 color maps at the 1:253,440 scale. Each map sheet is a GIF format image file between 60 and 140 kilobytes in size. They can be downloaded in 5-30 seconds and printed on standard laser and inkjet printers. If you have a black and white printer, built in color to black and white conversion routines will create a usable black and white map set. Simply print the color maps and they will automatically convert to black and white.

The maps are designed to be used in conjunction with either the standard US Forest Service 1/2 inch per mile recreation visitor maps, or USGS 7.5 minute (1:24,000 scale) or 15 minute (1:63,360 scale) topographic maps. We created the roadless map series at the 1:253,440 scale so you can easily create a set of roadless area overlays for the USFS 1/2 inch per mile maps. To make roadless overlays, print the roadless maps (as described below), and then enlarge them 200% with an enlarging copier. The maps can be enlarged directly onto transparent media.

Links to index maps are available at the top of this page. Each index map contains an overview of roadless area distribution, locator information such as major roads, towns, and the national forest boundaries, and a locator grid depicting the extent of each detailed map sheet. The index maps also contain a key to most of the symbols used on the higher resolution maps. To download a single sheet, click on the region of the index map covered by it. Index maps and detailed map sheets can be printed directly or saved for later use. To print, set the margins of your web browser to 0.25 inches on all sides, and turn off any header labeling. To save a map on your computer, use the ''Save As'' option under ''File'' on your web browser.

All maps sheets are public domain and may be freely distributed everywhere. However, the entire dataset is draft and contains no guarantee of accuracy. If you note errors, please submit them to us. Maps will be updated as errors are noted and corrected. Please send to suggestions for correction and improvement to Eric Beckwitt.

Errata: The following errors were discovered when the Sierra/Cascade Region map set was published: 1) land ownership in Nevada: maps show virtually all roadless areas on private land. This is error. We will fix it when we receive better land ownership data for Nevada; 2) SE Inyo National Forest: half of the White Mountains contain no roadless areas. This is error! White Mountains were missed by the SNEP study where this roadless inventory was first created. Next iteration Sierra/Cascade maps will include the White Mountains.

This new inventory is offered as a tool to use when seeking protection of California''s diverse and unique natural heritage. It is also a guide for those who simply desire to see firsthand the wildest and most remote corners of the Golden State. We hope you get a chance. Many of finest days of our lives have been spent in these lands.


The California Roadless Inventory was made possible by the generosity and dedication of many people and organizations. Special thanks to Charles Convis and Jack Dangermond (Environmental Systems Research Institute, Redlands, CA), Jil Zilligen (Patagonia, Inc.), Forest Whitt (Hewlett-Packard Inc.), Catrina Black and Paul Spitler (California Wilderness Coalition), and Ralph Warbington (US Forest Service Region 5 Remote Sensing Laboratory, Sacramento, CA). To the following individuals we express our gratitude for encouragement at the project development stage and strong letters of support: Gary Snyder (Pulitzer prize winning poet and essayist), Scott Hoffman-Black (Sierra Nevada Forest Protection Campaign), and Jim Villeponteaux (Salmon River Restoration Council) and Felice Pace (Klamath Forest Alliance). Thank you all!