Last month, just as people were celebrating Rock Creek Park's 100th anniversary, the Bechtel Corp. -- designer of a light rail that could cross Rock Creek Park on the way from Silver Spring to Bethesda -- was making an inventory of trees along its right of way through the park. All trees with a greater than a six-inch diameter got numbered metal markers. Between 750 and 1,000 -- including maples, hemlocks, walnuts, oaks, willows and tulip poplars, many more than 60 years old and as tall as a hundred feet -- would have to go.

Most of the trees stand near Coquelin Run, a small stream with headwaters in Bethesda, which feeds into Rock Creek. Coquelin Run was one of the tributary "finger" parks envisioned in early designs for Rock Creek Park. These "fingers" were lopped off one by one as roads and developers took over, and the big park itself fought for survival.

Mostly young couples bought the lots along Coquelin Run in the '20s and '30s, because their location abutting the B&O Railroad made them cheap. The new residents planted trees as a shield against the passing freight trains.

In 1985 when the B&O abandoned the route, Montgomery County took advantage of the National Trail Systems Act, which gives priority in the sale of abandoned railroads to parks and trails. Soon, however, it became apparent that County Executive Sid Kramer and his planners wanted a light rail for the 4.4 miles between Silver Spring and Bethesda, with a narrow hiker/biker trail alongside to meet the requirements of the National Trail Systems Act.

When Gov. William Donald Schaefer offered $70 million from state funds to construct the light rail, the pleasant prospect of a hiker/biker trail, winding through 30 acres of parkland ranging from 66 feet to 250 feet wide, faded.

At first, only the 1,000 or so people who live in single-family homes, condos and apartments along the abandoned track objected to the advent of 40 mph light-rail trains running from 6 a.m. until midnight and every three minutes during rush hour. But as the Department of Transportation raised the estimated cost for the rail system, including tunnels and bridges, from $45 million to $70 million and finally to almost $150 million, other county residents, already in revolt against high property appraisals, became concerned. When the State Board of Transportation released figures showing that the light-rail project around Baltimore was already over budget by 48 percent, even more people took notice.

Neal Potter, almost surely the county's next executive, is one of them. He says he wants to review the trolley project. Any review should consider not only the objections of nearby residents and the rising cost but also:

That the Bush administration wants to decrease the federal subsidy for Metro, which could add $135 million to $351 million to Montgomery's share of Metro support before the Red, Yellow and Green lines are completed. In the face of such expenses neither the state nor the county can afford a light-rail venture.

That light rail won't alleviate traffic problems on East-West Highway, either, as some of its proponents have claimed. The Georgetown Branch amendment to the master plan passed last November by the county council and signed by the executive specifically stated that a light rail would have a negligible effect on East-West Highway traffic.

Developers support light rail because it would remove the cap on construction in Montgomery County, which prohibits building unless transportation is either in place or on the way. The day the first shovel of earth is turned over to build the new light rail, exaggerated and unproven claims of future ridership will be used by developers to put up buildings that will add more people to the congestion from which the area already suffers.

For $2 million, the county could instead create a hiker/biker trail on that railroad right of way. Such a trail would not only hold the land for future use but would extend the park system and save up to 1,000 trees in one of the last natural wooded areas in lower Montgomery County.

Chevy Chase appraised the value of 70 trees it lost in last year's big storm at $1.02 million. At this rate the monetary value of the trees that will be felled near Coquelin Run is $109 million. But the loss to Montgomery would not be measured in dollars alone.

-- Dallas Read