To most area residents the name Cabin John conjures up a little-known stream valley, named for a squatter who built his log cabin here about two centuries ago.

Today's Cabin John Valley is almost all wooded, undeveloped parkland, from the stream's mouth below MacArthur Boulevard, eight miles to its source above Montrose Road. Its trails beckon the hiker, naturalist, jogger, history buff, camera fan or seeker after solitude and natural beauty. The rapid-flowing creek is well-shaded by large trees for almost its entire length. The stream descends nearly 400 feet in its rock-strewn course toward the Potomac, with large pools succeeding shallow rapids and occasional cataracts.

The trails are readily accessible from six major highway crossings: MacArthur Boulevard, River Road, Bradley Boulevard, Democrary Boulevard, Tuckerman Lane and Montrose Road. The stream lies west of and parallel to I-495 much of the way. Well-defined but informal trails parallel the creek along most of its course. More extensive paths, including a nature trail and picnic grounds, beckon the visitor to Cabin John Regional Park, between Westlake Drive and Tuckerman Lane.

A map recently published by the Park and Planning Commission identifies points of interest in this valley and shows trails, streets and highways. For 70 cents, you can get it at the commission's office, 8787 Georgia Avenue, Silver Spring.

A rewarding fall hiking plan would be to follow the entire length of the creek in several trips, starting near the mouth at MacArthur Boulevard and ending at Montrose Road. Either retrace your steps along the creek or map out a route through streets in the nearby community, the heavily used Seven Locks Road can be dangerous.

Park off MacArthur Boulevard off Wilson Lane, or cross the Union Arch Bridge, parking near the recreation center to you right. This sandstone bridge was built during the Civil War to bring in the city's water supply from Great Falls. The locked brick building in the recreation area was once a gas house serving the Cabin John Hotel, a noted summer resort that stood across the road at the turn of the century.

A well-defined trail leads downhill to the creek, then upstream toward River Road. This soon becomes a bridle trail and crosses over to the east side, then north toward I-495. You can stay on the left bank, but a rocky, steep slope makes the path difficult.

At Booze Creek, within sight of the Interstate span, the path crosses to the far side and continues a fifth of a mile along the stream to a unique redbud stand, a beautiful sight in the spring with the trees clothed in masses of red flowers.

At Seven Locks Road you pass one of several stone quarries in the area. Keep to the left, looking for an old farm road, now a trail that leads to the left into a large stand of mature white pines, unique in this area. You can recognize this old road by the low stone retaining wall along one side. Return to the creek and continue upstream to Carderock Springs Road, then into River Road.

The route from River Road to Bradley Boulevard follows the creek's right bank. It begins in an unattractive area where quarry refuse has been dumped over the years and then covered over with soil. But you soon enter the shaded woodland trail that leads past three historic points. About half a mile upstream the trail skirts a long, narrow marsh, home of many aqustic plants including the attractive arrowhead and the rare tree clubmoss, nearby on the slope. many frogs find their home here. The trail continues to Bradley Boulevard, past the site of a once-extensive stone quarry and an early-19th-century trolley-line powerhouse, now a private residence.

The trail segment upstream to Democracy Boulevard is popular with local residents. There's a heavy growth of mountain laurel, and many veneable hardwoods. You soon reach the trace of Old Seven Locks Road, near an old ford. It's best to follow this old right-of-way to the right to the present-day highway, crossing over and continuing along the former road, now used only by hikers and joggers. American pennyroyal, base for an herb tea, grows along the old pavement, and there are fruit trees that still bear, in the neighborhood of an old homesite. You may also wish to inspect the marsh to your left, close to Seven Locks Road, home of the rare cardinal flower and several other unusual marsh plants.

Cross the boulevard and pick up the trail into the regional park, at the site of the new nature center. Turn right on reaching the power line and follow the dirt road to the cross trail, left into the park, and onto the nature trail. Go downhill back to Cabin John Creek and upstream to Tuckerman Lane.

Take an optional short detour to an extensive marsh, easily accessible via the road into the maintenance yard, and then downhill through the marsh. Here you'll see all sorts of aquatic plants, mainly cattaila. Retrace your steps to Tuckerman Lane, crossing over the road that leads to the youth group camping area.

Follow this road to where it veers uphill to the right. Your route is the woods trail, along the creek. You soon skirt a marsh and pass an abandoned walled-in spring. The trail is little used here and overgrown is spots. Take the cross-valley path along a sewer or water line to the much more used route on the other bank.

On approaching the Montrose Road interchange, you pass about 250 feet of the millrace of the 19th-century Boone's Mill. Easiest exit to the highway is via Greenleaf Avenue or Goya Drive.

You should also make the acquaintance of Buck Branch, a major tributary of Cabin John Creek. Its source is at Willowbrook Drive, north of Bell's Mill Road. It joins the main stream about a third of a mile south of Democracy Boulevard, near Gainesborough Road, the best access to the trail.

This walk of about 2 1/2 miles, along a sewer line installed more than a decade ago, starts near the site of a ford and the remains of seveal farm buildings. many old trees survive along the stream banks - a sycamore 39' in diameter and a white oak 4'7' in diameter, both more than a century old.

You also pass a miniature waterfall above Bell's Mill Road, and the slopes there are covered with mountain laurel. This evergreen shrub, related to the rhododendron, is especially showy in June, with masses of white to pink flowers.

A suggested return route is via Gainesborough Road. Go right on Willowbrook, and right on Tuckerman Lane, two blocks.