YOU DON'T have to look much further than the name to get the idea that an event, also known as a horse trial, is more than just another horse show. For spectators, it's one-stop shopping for three equestrian sports: For elegance of dressage, the steeplechase-style gutsiness of cross-country and the suspenseful excitement of stadium jumping all take place in one day at the location. It's a grueling test of bravery, discipline and conditioning for both horse and rider.

Combined training events evolved from trials of cavalry horses, when mounts needed the style to perform in parades, the heart and toughness to carry vital messages in battle at great speeds, and the stamina to provide transportation over vast distances. Three-day eventing has been an Olympic sport since the turn of the century, although the one-day, lower-level version has shown its most significant increase in popularity recently. Over the past decade, entries in horse trials have doubled.

As 10-year veteran eventer Gretchen Butts explains, horse trials have avoided the elitist reputations of show jumping and polo. "It's the least expensive sporting discipline. It doesn't matter what the horse looks like, it's how he performs." She says that while the sport remains very open to "backyard" horses, particularly at the lower Novice and Training levels where the vast majority of eventers compete, the increase in popularity has brought about some positive changes.

"The caliber of the horses is higher and more skill and knowledge of rules is needed from riders. There are more delineated goals for horses and what should be asked of horse/rider combinations. Riders need to be more savvy." Event riders also tend to be older than those in some other equestrian sports, with many continuing or just beginning to compete well past thirty.

Jean Prescott, a dental hygienist who has neatly arranged her work schedule to leave time to school her two event horses, says she rode in hunter-jumper shows most of her life. But, four years ago, she "did one event and there's no looking back." She feels the quality of riding is higher and the scoring more objective in eventing than show-jumping.

The Waredaca Farm Horse Trials, capping off the local season this Saturday and Sunday are among the best respected on the East Coast. About 250 riders from as far away as New York and South Carolina will compete on the farm's 230 acres of sprawling green courses.

Dressage begins at 8 both days, with competitions at different levels going on in separate arenas simultaneously. At first glance, dressage is the least exciting of the event phases, but for horses and riders, it requires intense concentration and discipline. Its prescribed movements are probably best compared to figure skating. The top scores go to horses that move with fluidity and show a certain pizzazz or "presence" in the ring.

Cross country follows, on a course that stretches for more than a mile over as many as 10 challenging obstacles. Riders preview the course before the event, but horses must compete at speeds of up to almost 20 miles per hour without knowing what's ahead. They have to be bold and unhestitatingly trust and obey their riders. Show officials will gladly make suggestions on the best spots to watch -- and the most formidable fences.

After time out for a picnic or snack at the refreshment stand, stadium-jumping begins. It's a final test of the horse's fitness and obedience following a tough morning. Fences are brightly painted and set in configurations that require considerable gymnastic ability, with whimsical decorations to try a hard-ridden horse's mettle. WAREDACA

is at 4015 Damascus Road (Route 650) in Gaithersburg. Its big red barn with "Camp Waredaca" in large white lettering, as well as a field full of horse trailers, should make it easy to spot. Events start at 8 a.m. and run till 5, Saturday and Sunday. It's free. 774-2862.