*Saturday: CPA 1040 8-K, Rash Field, 9 a.m., 882-5455; YWC 10-K, Severna Park, 946-4340; Byron 15-K, Emmitsburg, 10 a.m.; Credit Union 5-K, Aberdeen Proving Ground, 9 a.m., 272-7600; A Place for Your Pace, Loch Raven, 8 a.m., 566-RUN2; Clean Water 10-K, Washington; YWCA 10-K, Annapolis City Dock, 956-4340.
* Sunday: 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 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.
* April 27: Fastbreak 5-K, Boys' Latin School, 8:30 a.m.; Lady White Rose 5-K, York (Pa.) YWCA, 9:30 a.m., (717) 741-3836; Track Run, Anne Arundel CC, Arnold, 8 a.m.
* April 28: Clyde's American 10-K, Downtown Columbia, 8 a.m.964-1998; BRRC 10-K championship, Loch Raven, 9 a.m.; Reservoir 50-miler (limit 100), 7 a.m., 668-8609; Crusader 8-K, St. Paul's School, 8:30 a.m., 494-8649; GW Parkway Classic, Washington, 8 a.m., (703) 548-1548.
* Future Book: Bay Bridge Run, May 5; John Carroll 5-K, Bel AirMay 5; Lilac Bloomsday, May 5; Nike Women's Race 8-K, Washington, May 12; Constellation Classic, May 26; Baltimore Triathlon, June 23.
* Marathons: Mendocino, Calif., and Aurora, Colo., SaturdayCincinnati, Ohio, and Toledo, Ohio, Sunday; Drake Relays, Des Moines, Iowa, and Flushing Meadows, N.Y., April 27.