Library Groundbreaking

Groundbreaking for the first regional library in Loudoun County will take place at 10:30 a.m. Saturday at the library site adjacent to the Loudoun campus of Northern Virginia Community College. A reception will follow at the Visitor Center in the Cascades development. Call 777-0368.

Folk Concert in Leesburg

Schooner Fare, a folk trio form Portland, Maine, will perform Sunday evening at the Courthouse Concert. The performance, sponsored by the Bluemont Concert Series, begins at 7 p.m. on the courthouse lawn in Leesburg. A donation of $2 is requested. Call 777-6306.

Sterling Pre-School Applications

The Sterling Annex Pre-school is accepting applications for the 1990-91 school year. A $10 nonrefundable registration fee is due at the time of registration. Call 430-6673.

Seneca Ridge Recycling

The Seneca Ridge recycling center will be open from 8 a.m. to 4 p.m. Saturday. Bring aluminum and tin cans, some cardboards and plastics, glass and newspapers to Seneca Ridge Middle School. Call 450-0639.

Marshall Committee Organizing

The Leesburg Marshall Campaign Committee will hold an organizational meeting at 8 p.m. Monday at St. James Episcopal Church, 14 Cornwall St., Leesburg. The committee oversees a program to inform local residents about World War II Gen. George C. Marshall, architect of the postwar European Recovery Plan, and his Leesburg home, Dodona Manor. Call 777-1880.

Colonial Bike Tour Registration

The American Lung Association of Northern Virginia is accepting registration for the fifth annual Colonial Virginia Bike Tour scheduled for Oct. 5 to 7. Last year, the tour was filled by August. Cyclists will travel 100 miles through Williamsburg, Yorktown, Jamestown and Surry County, and will receive two nights lodging, all meals, medical and technical support. Cyclists must pay a $25 registration fee and raise at least $275 in pledges. Call the lung association office in Fairfax at (703) 591-4131.

Sky Meadows Schedule

This weekend at Sky Meadows State Park: a two-mile hike from 10 a.m. to noon Saturday; a campfire singalong from 8 to 9 p.m. Saturday; and a bread-making and butter-churning demonstration from 1 to 3:30 p.m. Sunday. All events are free; $1.50 is charged for parking on weekends. The park is accepting registrations until July 27 for its junior ranger-historian program for children ages 8 to 11. The program costs $5 and will take place from 9:30 a.m. to 12:30 p.m. on the first four Wednesday mornings of August. Call (703) 592-3556.

Chamber of Commerce Anniversary

The Loudoun County Chamber of Commerce will sponsor a 30th anniversary party from 5:30 to 9:30 p.m. tomorrow at Loudoun Valley Farms in Purcellville. Admission is $15. Call 777-2176 or 478-1050.

'Reptile World' Demonstration

The Middleburg Community Center will sponsor "Reptile World," a educational demonstration featuring a boa constrictor, a python, lizards and a crocodile, from 6:30 to 8 p.m. Wednesday in the amphitheatre. A $2 donation is requested. Call 687-6375.

Artists Sought for Studio Tour

The Loudoun Arts Council is seeking artists in eastern Loudoun and Middleburg willing to open their studios for the third annual Artists Studio Tour the first week of November. Artists wishing to participate may write to 1990 Loudoun Arts Council Studio Tour, 16 Loudoun St. S.W., Leesburg, Va. 22075 or call 478-1954. The deadline is Aug. 31.