* Saturday: Hagerstown Suns 5-K, Municipal Stadium, 1 p.m.; No Frills Biathlon, Frederick, 10 a.m., 882-6103; St. Paul's School 8:30 a.m., 494-8649; Kent AC Biathlon, Chestertown, 778-3148: BRRC A Place for Your Pace, Loch Raven, 8 a.m., 566-RUN2; Millrace 3-miler, Murray Center, 8:30 a.m., 396-0808.
* Sunday: File Fast Five Trails, Ashton, 9 a.m., 566-RUN2; RASAC Covered Bridge 6-miler, Joppa, 8 a.m., 879-9294; Sallie Mae Cherry Blossom Chaser 10-K, 8 a.m., West Potomac Park, Washington, (202) 728-6456; Patriots' Cup 8-K, George Mason Univ., 9 a.m., (703) 532-3215.
* April 15: 95th Boston Marathon, noon, Hopkinton, Mass.
* April 17: Westminster Main Street Mile, JCK Center, Westminster, 7 p.m., 857-5427.
* April 20: CPA 1040 8-K, Rash Field, 9 a.m., 882-5455; YWCA 10-K, Severna Park, 946-4340; Byron 15-K, Emmitsburg, 10 a.m., Place for Your Pace, Loch Raven, 8 a.m., 566-RUN2; Clean Water 10-K, Washington.
* April 21: Parkville Jaycees 5-miler, Parkville Shopping Center, 9 a.m., 444-9437; Fritzbe's 10-K, Rockville, 8 a.m., 353-0200; BRRC Bull Roast, Tall Cedars of Lebanon; Amish Country PTC half-marathon, Lancaster, Pa., RASAC Mountain 5 miler, Rocks State Park, 8 a.m., 836-1784; World Bank 8-K, Washington, 8:30 a.m., (202) 473-1791; Dundalk Triathlon, Dundalk CC, 10 a.m., 285-9690; Climb (stairs) to the Top, World Trade Center, 11:30 a.m., 560-2120; Penn Relays Distance Classic; Hopkins Spring Fair 8-K, JHU, 8:30 a.m., 494-8649.
* Future book: Boys' Latin Fastbreak 5-K, April 27; Lady White Rose 5-K, York, Pa., April 27; Track Run, Anne Arundel CC, April 27; Clyde's American 10-K, Columbia, April 28; BRRC 10-K championship, Loch Raven, 9 a.m., April 28; Reservoir 50-miler, April 28; Lord Baltimore 10-K, April 28; GW Parkway Classic, Washington, April 28; Bay Bridge Run, May 5; John Carroll 5-K, Bel Air, May 5; Lilac Bloomsday, May 5; Nike Women's Race 8-K, Washington, May 12; Constellation Classic, May 26; Baltimore Triathlon, June 23.
* Marathons: Brookings, S.D., Saturday; Boston, Monday; Mendocino, Calif., and Aurora, Colo., April 20; Cincinnati, Ohio, and Toledo, Ohio, April 21.