* ON THE GOOD FOOT: Looking for a way to jump-start your spring? The Potomac Appalachian Trail Club on Tuesday will head out to the Old Dogwood Route on the Appalachian Trail for a 35.7-mile hike. Yes, 35.7 miles.

Seventysomethings Chris Nolen and Cliff Noyes are leading the trek ("We have a couple people who are older than I am . . . it's not a matter of age," Nolen said), which contains a 4,000-foot elevation gain and extends from Snickers Gap to the 4-H Center north of Shenandoah National Park. Those who drop by the wayside will be gathered up later in the day. "You have to be really into it," Nolen added. If you are, call Nolen (chrishiker@erols.com) at 301-469-8931 or Noyes (cliff.noyes@juno.com) at 703-451-5181 for more information. Non-members are welcome. . . .

Georgia Murray, the Appalachian Mountain Club's staff scientist for air quality, will give a 45-minute talk and then co-lead a six-mile hike around Sugarloaf Mountain in Maryland on May 3. The group will meet at the East View parking lot at 10:15 a.m. Non-members are welcome. To register, call Paul and Mary Ann Ray at 410-745-6852.

* DIG IN: The Potomac Conservancy, the Loudoun Soil and Water Conservation District and the Northern Virginia Regional Park Authority are looking for volunteers to help a seedling planting project at Aleck's Creek, which flows into a tributary of the Potomac River. The plan is to plant hundreds of seedlings, which eventually will boost water quality in the Potomac and Chesapeake Bay. No experience is needed and families are welcome, but bring lunch, water, long pants and work gear. Site is Temple Hall Farm Park in Leesburg, 10 a.m. to 3 p.m. on Wednesday and Thursday. For details, call the Potomac Conservancy's Matt Berres (riverrat@potomac.org) at 703-276-2777, ext. 203, or visit www.potomac.org or www.growingnative.org.

* WALL TO WALL: The Mountaineering Section of the Potomac Appalachian Trail Club will host a rock climbing event for beginners on Sunday at Great Falls National Park in Virginia. Participants will meet at 8 a.m. in the parking lot (ask at the gate for directions to the "climbers lot") and PATC-MS climbers will help out on the rocks with tips and technique. Non-members are welcome, but you must get in touch with trip leader Andy Britton (TallAndyB@aol.com) and sign a liability waiver beforehand. To download the waiver, visit http://www.patc.net/chapters . . .

Climber-kayaker Court Ogilvie will be the featured speaker-slide show presenter at the Canoe Cruisers Association's meeting on Wednesday at the Clara Barton Community Center at 75th and MacArthur Blvd. in Cabin John. Event is free, starts at 7 p.m. and is open to the public.

* GET A CLUE: The Wilderness Safety Council will host a Wilderness First Aid Class in Alexandria on May 3-4. The combination of classroom study and hands-on training will meet the standards for two-year certification. For details, visit http://wfa.net.

-- John Mullen

mullenj@washpost.com