* OUT THERE: One summer, I climbed with a roommate to one of the peaks at Park City ski area in Utah only to stumble upon a large, clawed-out cave entrance just out of bounds. I turned tail and ran, afraid of what toothed mammal might burst out of there. I still don't know what lived in that cave and, closer to home, wish I knew more about the animals who live with and around us near Washington. One way to begin is to take part in the Audubon Naturalist Society's "Introduction to the Natural History of Mammals," which will run from noon to 8 p.m. on Saturday at the Rust Sanctuary in Leesburg. The class, led by Tammy Schwab, will focus on identification skills and will include visits to den sites. For details, call 703-669-0000 or visit www.audubonnaturalist.org.

* AROUND TOWN: Got cabin fever? Join the Potomac Appalachian Trail Club and the Sierra Club on Thursday for a nine-mile hike through Glen Echo and along Cabin John Creek and the C&O Towpath. The trek, considered moderately demanding, moves across variable terrain and starts at 10 a.m. Bring lunch and much water, leave pets at home. Directions to meeting spot: From the Beltway, take Exit 41 and go East on Clara Barton Parkway until it merges with Cabin John Parkway. Take Cabin John exit, go left over bridge and right onto MacArthur Boulevard. Park entrance is 11/2 miles ahead. For more information, contact Henri Comeau at 703-451-7965 or henricomeau@aol.com.

* FISH WISH-LIST: The Northern Virginia Chapter of Trout Unlimited will meet on March 6 for fly-fishing guide Jeff Lewatowski's tales of pursuing striped bass on the Susquehanna Flats and the upper sections of the Chesapeake Bay. The public is welcome; event starts at 7:30 p.m. at the Vienna Volunteer Fire Department, 400 Center St. SE. Visit www.nvatu.org for details . . . The National Capital Chapter of Trout Unlimited will host its 28th annual Angling Show on March 8 from 10 a.m. to 5:30 p.m. at the Landon School in Bethesda. Headliners include Lefty Kreh and Dusty Wissmath. Admission is $10 for adults; those 16 and under get in free. For information, call 202-363-0437 or visit www.ncc-tu.org.

-- John Mullen

mullenj@washpost.com