Make tracks on Saturday to George Washington Birthplace Monument, 38 miles south of Fredericksburg, for "Indian Heritage History Day." You'll be able to watch members of the United Rappahannock Indian Tribe demonstrate basket weaving, patterned beadwork and pottery fired over an open campfire. There'll also be plenty of traditional chow and a genuine pow- wow in the afternoon.

Admission to the following activities is free unless otherwise noted.

SENIOR CITIZEN PARTY -- Friday, 10 a.m. to 2, Good Luck Community Center, 8601 Good Luck Rd., Lanham. Dancing, ceramics, exercise and needlework. Bring a lunch and a friend. 552-1093.

OLD TOWN TOUR -- Friday, 8 p.m.; Saturday, 10:30 a.m., 8 p.m.; Sunday, 2, Ramsay House Visitors Center, 221 King St., Alexandria. Take a special summer tour retracing the steps of George Washington and Robert E. Lee with a colonial-attired guide through the cobblestoned streets of Old Town Alexandria. Adults $2; ages seven to 15, $1. 548-0100.

BOOK SALE -- Friday, 10 to 8; Saturday, 10 to 6; Atrium, Cabin John Mall, 11325 Seven Locks Road, Potomac. 983-0400.

TRACTOR SHOW -- Saturday and Sunday, 10 a.m. to 8 p.m., Izaak Walton League Conservation Park, Mullinix Mill Road, Damascus (I-270 north to Germantown Exit, follow 118 east to Rte. 27 north; then take Rte. 108 east to Mullinix Mill Road turning left; park 11/4 mile on left), "Third Annual Damascus Steam, Gas and Tractor Show." Two days of steam engine demonstrations, flea market and crafts, parades, wagon rides, antique car shows and more. Free admission; parking $2 per car. 972-1953.

YARD SALE -- Saturday, 9 to noon, Belair Mansion, 12207 Tulip Grove Dr., Bowie, Md. (take U.S. 50 to Rte. 197 north; 1.3 miles to Tulip Grove Drive, mansion is 1/2-mile on right). A yard sale featuring old street signs of Bowie, clothing, ceramics, books, used home appliances, aquarium, refreshments and more. 301/262-3463.

SPRINGFIELD FESTIVAL -- Saturday, 10 to 6, Springfield Plaza and Garfield Elementary School, intersection of Old Keene Mill Road and Backlick Road, (from the Beltway, exit at Springfield Exit, turn on Old Keene Mill Road going west, festival is 1/4 mile at intersection), "First Annual Springfield Festival." Arts and crafts, flea market and auction at plaza; entertainment and food at school. 978-2286 after 6.

INDOOR YARD SALE -- Saturday, 10 to dusk, District of Columbia Association for Retarded Citizens, 900 Varnum St. NE. Food, bingo, auction beginning at 2; raffle at 4. 829- 2989 or 636-2950.

FLEA MARKET -- Saturday, 10 to 3, Allen Pond Ice Rink, 3330 Northview Dr., Bowie (U.S. 50 east, right on Rte. 197; make first right on Northview), "Chesapeake Wildlife Sanctuary Flea Market." More than 40 booths selling bric-a-brac, crafts, bake sale, refreshments and more. 249-1228.

HAMMER AND TONGS -- Saturday and Sunday, 11 to 4, Colvin Mill Run Park, Great Falls, Va. (take Rte. 7 off Beltway past Tysons Corner to the mill entrance on the right). See hammer-wielding strongmen (and women) demonstrate the vanishing art of blacksmithing; you'll even be able to purchase the fruits of their labor. 749-2771.

INDIAN HERITAGE DAY -- Saturday, 11 to 4, George Washington Birthplace National Monument, Washington's Birthplace, Va. (take I-95 to Fredericksburg and Rte. 3 east; turn left on Rte. 204, which dead ends into park), "Indian Heritage-History Day." Bring a chair and a blanket for a day-long presentation by members of the United Rappahannock Indian Tribe. From 11 to 1, you can see cooking and craft demonstrations; from 2 to 4 watch a traditional pow-wow and dance. 804/224-0196.

CIVIL WAR ENCAMPMENT -- Saturday, 11 to 6; Sunday, 9 to 3, Grounds of Beall-Dawson House, 103 West Montgomery Ave., Rockville (from I-270, exit on Rte. 28 east, left at fourth light onto Montgomery Avenue; Beall-Dawson House is eight blocks on left; three blocks from Rockville metro stop), "Fourth Annual Civil War Encampment." Two days of living history with Union and Confederate Soldiers. Saturday highlights include a calvary demonstration at 2:30, and a soiree with old-fashioned live music in the Beall-Dawson house from 8 to 10 p.m. ($3). Battle skirmish Sunday at 1:30. All activities on the grounds are free; admission to Beall- Dawson House, $2. 762-1492.

NAME THAT TREE -- Saturday, 7 to 8:30 p.m., Huntley Meadows Park, Harrison Lane and Lockheed Boulevard, Hybla Valley. (Beltway to U.S. 1 south 3.5 miles to Lockheed Boulevard, make right; park entrance on left at Harrison Lane). Join a park naturalist who'll teach you how to identify various trees, including willows, aspens, elms, maples and more. 768-2525.

COMET HALLEY -- Saturday, 8:30 to 9:30 p.m., Outdoor Amphitheater, Burke Lake Park, Burke. (I-66 west to Rte. 123, straight ahead eight miles; park entrance on left). An expert from the Smithsonian Air and Space Museum presents a slide show about comets; afterwards, look through a telescope. 451- 9588.

ANTIQUE CAR SHOW -- Sunday, 9 to 4, Oatlands Plantation, U.S. 15, six miles south of Leesburg, (take I-66 west to U.S. 50 west to U.S. 15 north six miles, Oatlands Plantation on right), "Fourth Annual Antique Car Show." See a wide range of antique cars, buy old parts at a flea market; food and jazz; arts and crafts. Adults $3; seniors and children seven to 18, $3. 703/777-2589 or 777-3174.

WALK ON THE WILD SIDE -- Sunday, 7 to 8, Braddock Road Park, 13241 Braddock Rd., Clifton, Va., (Beltway Exit 5-W, Braddock Road; park entrance 10 miles on left, just after crossing Clifton Road), "Summer Blossoms." Join a naturalist for a meadow walk in search of area's brightest wildflowers. 451-9588.