Led by a heavily perspiring owl who contracted jungle foot back in the Second World War, a band of ecological activists, politicians and small children marched from Gaithersburg to Rockville yesterday along a highway littered with cans, bottles and other evidence that told them their cause was just.

"The citizens of Maryland are sick and tired of having their roads and highways strewed with cans and bottles," hooted Malcolm King, 70, who was sweltering in the lower half of a suit of brown polyester fur, while cradling the large beaked face of Woodsy Owl, the antipollution mascot.

"I'd go on to Rockville, but my feet won't let me," King sighed as he mopped his sweat-soaked face with a handkerchief he had providentially tucked behind one of Woodsy's plate-sized eyes. "I was with the Seabees in Guam and my feet got jungle rot. I'll drive most of the way and walk in."

On to Rockville by foot, however, went the rest of about 20 marchers, carrying banners and signs into a slight head wind, raising their thumbs to acknowledge the horns of passing cars, talking merrily of legislation and litter, and stooping frequently to pluck up several cases worth of beer and soda cans.

For those who had begun the "Bottle Bill Walk Across Maryland" two weeks ago at the West Virginia state line, and for those who joined in for a five-mile stroll along a route they had often driven but seldom walked, the morning revealed a length of Rockville Pike in all its splendor. Not just the familiar fast food attractions like McDonald's or Wendy's, where sloe-eyed waitresses chatted outside, but lesser known establishments like the offices of R. H. Teunis the optometrist, the Denture Center, the Scuderi Brothers Autobody Shop and the Montgomery County Solid Waste Transfer Station, a sight that occasioned much discussion about a proposed incinerator.

Groups of activists banded together as Citizens Against Waste are walking across Maryland and converging on Annapolis from the west, the south and the north to press for passage of a beverage container deposit law similar to measures now on the books in nine states.

The bill has been before the Maryland legislature since 1971, but it has been successfully opposed by a coalition of labor and beverage industry interests.

About a dozen people, now in two separate groups, are traversing the entire western length of the state with the intention of arriving in time for a large rally in Annapolis on Saturday. The opponents of the bottle bill plan to stage a counter demonstration, but proponents are optimistic.

"We're in good physical and political shape," said Jonathan Puth, who had made the trip from the West Virginia state line with Rachel Weiner, a 20-year-old design student working for Citizens Against Waste, and Milford Juten, a 73-year-old retired lawyer from Bethesda who put aside selling heat exchangers for home furnaces in order to "march against waste."

On a warm and sunny autumn morning, Juten's shorts, dapper beret and running shoes were better suited for marching against waste than poor Woodsy's togs. He sauntered along comfortably, yet his feet, with good reason, insisted that the distance be noted right to the fractions.

"As of yesterday we hiked 186.7 miles, no, excuse me, 199.3 miles," Juten said. "By today, we will have walked 214.4 miles, and by the time we get to Annapolis we will have walked 255.5 miles."

To start the morning off in Gaithersburg, the marchers listened to a Texas-based troubador named Bill Oliver perform his composition "If Cans Were Nickels:"

"Containers are a big convenience, but why are litter laws so lenient," he sang. By popular demand Oliver delivered an encore that ought to go to the top of the Ecological Hit Parade. It went: "Habitat, habitat, have to have a habitat."

The long-distance marchers had carefully mapped their route in advance. By car, they ferried ahead their equipment, including tents, sleeping bags, leaflets, bumper stickers, a James Watt dart board with a bullseye superimposed on the bulbous dome of the Interior secretary, and an orange tank of helium for the Bottle Bill Walk Across Maryland balloons. They have slept under stars and billeted with bottle bill sympathizers in various towns and counties.

By the time she reached Rockville, marcher Audrie Witney had amassed an unmanageable pile of flattened beer and soda containers, which she had wrapped in her white cotton sweater and cradled in her arms.

"This is almost as bad as when they were giving out free rabies shots and I stood in line with some lady's cat," she said. "That cat weighed a ton!"