* PATH, FINDERS: The Georgetown Visitor Center of the C&O Canal National Historical Park is offering free, guided, weekend bike rides along the canal. On Saturday at 10 a.m. a group will leave from Maryland's Great Falls Park for a 45-mile ride to Harpers Ferry, W. Va.

The towpath is not a difficult ride, but mountain bikes are suggested. You will camp overnight and return on Sunday. The camping is free, as is the van ride back from Harpers Ferry. However, you will have to bring food and biking gear (extra stuff can be stored in the van). A limited number of bikes are available, but it is requested you bring your own. The trip will be repeated on July 31-Aug. 1. For more information and to reserve a spot, call 202-653-5190. . . .

The Mid-Atlantic Off-Road Enthusiasts will gather on Thursday at 8 p.m. at McFadden's, 2401 Pennsylvania Ave., NW, for a (rebroadcast) viewing party of the Tour de France as Lance Armstrong & Co. gear up for serious climbs in the Alps. For details and weekly ride schedules, visit www.more-mtb.org. Also, MORE will host its annual summer picnic and the opening of the perimeter riding trail at Rosaryville State Park in Upper Marlboro on July 25. Rides start at about 10 a.m., followed by the food fest. Be sure to bring your favorite dish. Non-members are welcome.

* WATERING HOLE: The West Virginia Rivers Coalition will host the sixth annual Potomac River Reception on Thursday at 7 p.m. at the Old Ebbitt Grill, around the corner from the White House at 675 15th St., NW . The fundraiser costs $40, and tickets will be available at the door. The public is welcome.

Included in the price are drinks and finger food. Ed Merrifield, the Potomac River Keeper, will be a featured speaker, and Julie Keller's photography will be displayed. For more information, contact WVRC's Leslie Montgomery at 304-637-7201.

* MOVING AHEAD: The 12th annual Riverwatch Triathlon and Duathlon, which doubles as the Maryland State Triathlon and Duathlon championships, will be held on July 25 at North East Community Park in North East, Md. The triathlon is composed of a .75-mile swim, a 16-mile bike ride and a three-mile run. The duathlon is made up of two three-mile runs and a 16-mile bike ride. For details and directions, visit www.triath.com. To volunteer, call 410-593-9662.

* THINGS AFOOT: REI will offer Backpacking 101 at its Baileys Crossroads store on Wednesday at 7:30 p.m. The clinic is free. Visit www.rei.com for details. . . .

The Potomac Appalachian Trail Club will go for a hike on July 25 starting at 9 a.m. along the Billy Goat trail in Great Falls, Md. Non-members are welcome. To sign up, contact Georgeann Smale at gsmale99@yahoo.com.

-- John Mullen

mullenj@washpost.com