THREE AREA DANCE companies -- one from Rappahannock County, one from College Park and another from the heart of Adams Morgan -- will present concerts here this weekend, each performing at least one new work.

For the past 10 years, choreographer Sally Nash has made her home in rural Virginia. Together with her Last Minute Wood Company, she returns to the urban jungle this weekend to present "Box 48." Based on letters Nash has received over the past decade, this work uses words, movement and a vibrantly eclectic score by Tom Espinola to explore such subjects as religious awakening, mother's cooking, tangled relationships and the creative process. The six dancers have a natural, unstudied look about them, and Nash's ideas are conveyed via a simple, lyrical movement style.

Improvisations Unlimited, the young performance troupe in residence at the University of Maryland, has helped many audiences to understand both how intriguing and rigorous the improvisatory process can be. In addition to their work in this area, the company boasts a repertoire by a variety of first-rate local and out-of-town artists. This time around, they will premier two new works -- one by New York choreographer Jerry Pearson, the other by company director Meriam Rosen.

Choreographer Carla Perlo and her husband, percussionist Steve Bloom, must be one of Washington's most hard-working and optimistic couples. Though they must vacate their beloved Dance Place studio and performance center on January 31, they've assured Washington dance fans that a new space will be found post haste. This weekend, Perlo-Bloom & Co. will present three "farewell to the 18th Street space" concerts, featuring a new dance by Perlo, several other recent works and music by Bloom and associates.

SALLY NASH AND THE LAST MINUTE WOOD CO. -- 8 p.m. Saturday; 5 p.m. Sunday at Mount Vernon College Hand Chapel, 2100 Foxhall Road NW. $6. 331-3467.

IMPROVISATIONS UNLIMITED -- 8 p.m. Friday and Saturday at University of Maryland's EE Studio Theater. 454-4847.

PERLO-BLOOM & CO. -- 8:30 p.m. Friday and Saturday, 5 p.m. Sunday at The Dance Place, 2424 18th St. NW. $8; $7 students/seniors. 462-1321.