James Halfpenny's A Field Guide to Mammal Tracking in North America takes a similar approach to Rezendes's Tracking, albeit with less polish and more science. Halfpenny's shorthand and formula for recording tracks might be a little overwhelming for beginners. But his writing is detailed and informative, making his Guide a good companion volume to the Rezendes book.

Coordinates: $14.95. Johnson Books, www.tracknature.com

Part of the Peterson Field Guides series, Olaus Murie's Animal Tracks is small enough to carry in your day pack, making it an excellent choice for use on the trail. Check out the book's "Key to Tracks," a quick reference to the length and shape of common animal tracks. A small ruler for measuring tracks is printed on the book's inside back cover.

Coordinates: $18. Houghton Mifflin, www.hmco.com/trade

Sidebar: Get on Track

The fastest way to get up to speed on tracking is to take a workshop. Here are four schools that will put you on an accelerated path.

Tom Brown's Tracker School, Asbury, New Jersey Brown, a pioneer among modern trackers-turned-teachers, has made the wild Pine Barrens region of south-central New Jersey his classroom; he also holds workshops in California. For a $650 fee, participants learn stalking, camouflage, tracking, and skills in outdoor survival.

Coordinates: 908-479-4681, www.trackerschool.com

The Tracking Project, Corrales, New Mexico Led by master tracker John Stokes, the Tracking Project's classes draw heavily on American Indian lore. Courses last a week to a week and a half, and most cost approximately $800.

Coordinates: 505-898-6967, thetrackingproject@earthlink.net

A Naturalist's World, Gardiner, Montana Jim Halfpenny's and Diann Thompson's natural-history and ecology programs include tracking. Most of their classes, which range from two days to two weeks, cost between $150 and $450.

Coordinates: 406-848-9458, www.tracknature.com

Paul Rezendes's Photography and Nature Programs, Athol, Massachusetts Rezendes's day- and weekend-long courses in tracking run from $40 to $125. Coordinates 978-249-8810, www.mossbrook.com/rez

Tools

Topographical Map

Always carry a topo map. In addition to the topographical gradations that most maps don't have, topo maps feature useful landmarks, such as mountain peaks and backcountry cabins. With a scale of 1:24,000, topos are extremely accurate and detailed. You can order maps online from either the U.S. Geological Survey or from MapQuest.

Coordinates: $6.95. U.S. Geological Survey, www.usgs.gov; MapQuest MapStore, www.mapstore.com

Compass

To track an animal, you have to get off the trail and into the bush. If you want to find your way home, you'd better pack a compass. Suunto's MC-2G Global Compass should keep you headed in the right direction. Its "global needle" makes the MC-2G specially balanced for accurate tracking worldwide -- whether you're in Alaska or New Guinea.

Coordinates: $69.95. Suunto U.S.A., www.suuntousa.com

Knife

A knife is the most versatile animal-tracking tool of all. Use it to poke through the contents of raccoon scat (you're not going to use your fingers, are you?), or to cut cord to build a lean-to. The new Big Sky fixed blade from Buck Knives weighs only 2.5 ounces and features a black Obeechee wood handle, a lanyard hole in the handle, and a sturdy black sheath.

Coordinates: $70. Buck Knives, www.buckknives.com