Spring becomes the C&O canal -- but the brink of spring is a special time, before the leaves pop out on the trees to block the view of the river from the towpath.

The early wild things are coming forth. Along the canal, blue spring beauties can be found in sunnier places, and reddish-green skunk cabbage in wetter ones. Starting to green up are the willows. On spicebush and silver maple, buds are swelling.

One stretch of towpath along the canal is uncharacteristic of the bright sunny path. It's one of the secret places and a reminder of the season just past. Near Lock 8, the towpath becomes a bankless strand where the wind seems to pick up, even on clear, still days. As if seeking the sea, it churns the water on either side. Here can be seen the derelicts of winter -- the abandoned logs lodged among the bleached sycamores in the river, the rocks swept clean.

Shadows of sycamore trunks stripe the path. As you walk, there will always be a child of six or seven careening along on a small bike, frighteningly close to the water's edge, front wheel wiggling, now at canal's side, now at river's side, the rider never imagining any danger, the passerby picturing all sorts of mishaps.

Always in view along the stretch will be a man and a woman, and for every couple, a dog. Sometimes people come alone to walk their dogs. A young man in natty blue blazer and tie accompanies a shaggy poodle that has taken an impromptu dip, white curls gray with muddy water, about to shake itself dry.

Joggers abound for some reason, even though the rocks embedded in the dirt path surprise their ankles. They do not do miles; they do locks.

Other visitors come to the canal just to sit by the freshets, listening to the gurgling streams of spring, taking in the air. They close their eyes to the sun. The sight and sound of the occasional portage excites their interest: canoeists paddling ashore just short of a lock, then carrying the vessel around it. The canoe makes a peculiar screech as it slips down the bank and dips back into the water.

Down at Fletcher's Boat House, they're renting bikes and rowboats again. And Dan Ward, who works there, says that, barring any bad weather or high water, the fishing will be excellent this weekend. The white perch and herring have started to run. Fishing is fairly good even in the canal for largemouth bass, crappies, bluegills, sunfish, catfish and carp, in season. The boathouse sells bait and tackle.

Upstream at Great Falls Tavern, a couple of Canada geese have made their annual return. "They come every year at this time, raise their family and leave," says park ranger Gary Pieruccioni. Along with them can be seen wood ducks and mallards, and herring gulls along the river. Cardinals and chickadees are making most of the noise in the trees, with an occasional word from pileated woodpeckers. CANAL CAPERS BIRD HUNT -- This Saturday at 9, meet at Great Falls Tavern at the western end of MacArthur Boulevard to welcome the early-spring migratory birds with Grace Sims. Bring binoculars. 299-3613. SENECA LOCK HOUSE -- Saturdays and Sundays from 1 to 4 at the Seneca lock house, Girl Scouts in period costume talk about life along the canal and offer homemade goodies. In Seneca, off River Road. 299-3613. HIKE & LUNCH -- Saturday, March 26, the city of Rockville is sponsoring a hike and lunch on the C&O. Meet at 10 at the tavern or carpool from Civic Center Park at 9:15. Registration deadline is this Monday. Cost, $6 for Rockville residents and $6.50 for non-residents, includes lunch. 424-8000, ext. 340. SIGHTS & SOUNDS OF SPRING -- Saturday, March 26 and Wednesday, March 30, at 10, meet at Great Falls Tavern for a slide show and guided hike. OLD-TIME MUSIC -- Saturday, March 26 at 3:30, Jon Singleton plays Southern Appalachian music on period instruments at Great Falls Tavern. CANAL HISTORY -- Sunday, March 27 at 2, a slide talk on 96 years of the C&O Canal at Great Falls Tavern. ABNER CLOUD HOUSE -- Thursday, March 31 from 11 to 3, the Colonial Dames of America and the National Park Service will open the Abner Cloud house. This restored home is the oldest building along the canal. At the intersection of Canal and Reservoir roads NW, across from Fletcher's Boat House. RENTALS AT FLETCHER'S BOAT HOUSE -- Rowboats: $7 a day during the week; $8 on weekends and holidays; hourly rate (canal only), $4. Canoes (rentals start in April when the water is warmer, in case of overturnings): $7.50 a day on weekdays; $8.50 weekends and holidays; hourly rate, $4. Bikes: $5 a day plus tax; minimum $3 for 2 hours. If bad weather threatens, call ahead to see if the boathouse is open. At Canal and Reservoir roads NW. 244- 0461. RENTALS AT SWAINS LOCK -- Rowboats (for fishing): $2 an hour; $5 a day, plus tax. Canoes (canal use only): $3.50 an hour; $6.50 a day, plus tax. Bikes: $1.50 for the first hour, 75 cents each additional hour; $4.20 a day. They expect to be open this weekend, but call to confirm. On Swains Lock Road, off River Road. 299-9006..