Other events:
Maryland Native Plant Society
Sat: Chapman Forest South, Charles County
Sun: Ferns on the Gunpowder River (near Baltimore)
Sierra Club
Tue eve: Canoe & Kayak lessons at Fletcher's Boat House
Sun: American Chestnut Land Trust hike/canoe
Potomac Appalachian Trail Club
Many cabin and trail crew work trips.
Tue: SNP - Austin Mtn, AT, Furnace Mtn Trails (19 mi)
Wed: Rock Creek Park (5 mi)
Sun: George Washington NF, Massanutten & other peaks (9-14.5 mi, bus from metro)
Audubon Naturalist Society
Tue: Firefly Fling
Wed: C&O Canal, Riley's Lock
Fri: Sunset Safari at the National Zoo
Sat: Boundary Bridge (2.5 mi)
Sun: Paddle on the Patuxent at Jug Bay
Center Hiking Club
Tue eve: Old Town Alexandria (2-4 mi)
Fri eve: Glover, Whitehaven, and Dumbarton Oaks Parks (5 mi)
Sat: Historic Arlington Bike Tour
Sat: Big Meadows Waterfalls (10 mi, meets at Vienna Metro)
Sun: Jeremy's Run in SNP (11 mi, meets at Vienna Metro)
Northern Virginia Hiking Club
Sat: SNP - Brown Mtn/Big Run (10 mi)
Sat: South Run to Burke Lake (8 mi)
Sun: Sky Meadows (8.4 mi)
Sun: Hound Hike at Wakefield Park (5 mi)
Capital Hiking Club
Schedule wasn't up when we compiled this post; check the link now.
Washington Women Outdoors
Sat: Catoctin Valley bike ride to Waterford, VA (37 mi)
Sat: AT - Weverton Cliffs to Gathland (13 mi)
United States Botanical Garden
Mon eve: Tour of native plants in the National Garden
FOR KIDS
Rock Creek Park
Fri: Creature Feature (all ages)
Fri: make a clay pot in the American Indian tradition (ages 6+)
Sat: Just "fur" fun (all ages)
Sat eve: explore the sky with telescopes (all ages)
Sun: make a clay pot in the American Indian tradition (ages 6+)
Did we miss something? Post it in the comments.