The American Indian Heritage Festival on the Mall will be held from 11 a.m. to 7 p.m. Sunday and 12:30 p.m. to 7 p.m. Monday. For details call (703) 237-7500. Yesterday's Weekend section omitted the hours and telephone number.

It'll be a weekend of American heritage festivals and fairs as the country clambers to the pool, the shore, the country or in town to celebrate our 207th birthday. *On the Mall, the American Indian Heritage Festival will host thousands of Indians from tribes around the nation. There'll be a national powwow, dance competition, arts and crafts, cultural exhibits and native food. Linda K. Baker, the 1983 Miss National Congress of American Indians, and Iron Eyes Cody will make an appearance with the Red Land Singers, Hopi Dancers and the White Eagle Dancers. The free festival's at Constitution Avenue between 14th and 15th streets NW. *"Life, Liberty and Happiness" will be the theme Saturday at Colvin Run Mill's celebration. Contests include watermelon- seed spitting, climbing a greased pole, downing apple pie and calling in the farm animals. There'll also be square dancing, clogging by the Lowdown Cloggers and music by Pokeweed and the Mill Run Dulcimer Band. The fun is from 11 to 5 at the historic 19th-century mill, open to visitors in Great Falls, Virginia on Route 7, five miles west of the Beltway. Admission is $3 for adults and $1, kids. Call 759-2771. *The Flute Company pipes up to celebrate the holiday at Sully plantation with a two-hour concert of lighttclassical music on Monday. The plantation, built in 1794, has been restored and tours are included in the $2 admission (children, $1). Bring a picnic and a blanket and enjoy the day. From the Beltway take Route 50 west, then right on Sully Road for three-quarters of a mile. Call 437-1794. *Also on Monday, two Revolutionary War groups -- the First Virginia Regiment and the 71st Regiment of Foot -- will camp out in front of the National Archives on Constitution Avenue at noon. They'll perform a cannon and musket demonstration followed by a patriotic music concert at 2. Actor Glenn Taylor follows with a reading of the Declaration of Independence on the Archive steps. (The original will be on display throughout the day beginning at 10 in Exhibition Hall Rotunda). The honor guard will change every half hour and it's all free. *The Georgetown Waterfront will be the scene of the second annual Georgetown Fourth of July Fair starting Monday evening at 5. An upriver view of the monument fireworks is a bonus along with country barbequed chicken and corn, old fashioned midway carnival games, hot air balloon rides, pony rides and dancing to the sound of the Heptones. Advance tickets are $10; $12 at the door; children $5. Free parking in Georgetown could make the day unforgettable. Call 333-3577 for parking locations.