Citizens Alliance to Save Huntley Meadows has stepped up its efforts to fight Fairfax County's plan to build a $17 million four-lane parkway through the 1,262-acre park in Hybla Valley.

Fearing that county funds will become available for the unfunded road if Fairfax voters pass a major road bond referendum in November, the alliance held a two-mile hike Sunday to show opposition to the construction of the road that has been a county priority since the mid-1970s. More than 100 people, led by a local ecologist, walked along part of the proposed Van Dorn Street-Lockheed Boulevard Connector.

The alliance contends that the four-mile parkway, about 1 3/4 miles of which would be in the park, would upset the park's fragile wetlands environment. County officials support the four-mile road because it would provide a quick link between I-95 and Rte. 1 and relieve traffic on some residential streets. Officials also hope the road will be the key to the economic revitalization of the Rte. 1 corridor.

County officials say that an environmental assessment done in 1983 shows that no significant impact on the park would be caused by the road.

The environmental assessment done by the county was required by the Department of the Interior as part of the agreement when the federal government deeded the park, the county's largest, to Fairfax in 1975.

The Department of Interior, which must give final approval for the road before it can be built, will reevaluate the environmental impact once the road receives the final design from the county. The final design cannot be drawn up until money is available.

According to the county's 1975 agreement with the Department of Interior, the parkland could revert to the federal government if the county was found not to be using the land for conservation and recreation purposes.

Norma Hoffman, who heads Citizens Alliance to Save Huntley Meadows, said opposition to the road is growing. The group added 150 signatures to their antiroad petition last Sunday.

"We are adamant about taking the road out of the park. We understand the need for a transportation route, considering the anticipated growth in the area, but we think there should be an alternate route," Hoffman said.

Local ecologist Allan Studholme, who led the gathering through Huntley Meadows Park, said that Fairfax is "100 percent wrong" by saying that the road will not have a significant effect on the park. "Wetlands are a very rare kind of land in Fairfax County. It's a very fragile type of habitat," Studholme said.

"While it's a small proportion of the park area to be taken by the road , it will have an effect that will change the park remarkably. It's just like shooting a guy with a bullet. It makes a small hole, but it kills him," Studholme said.

Lee District Supervisor Joe Alexander, a major proponent of the Van Dorn-Lockheed road, said that various federal, state and county agencies and citizen groups have been consulted to determine ways of lessening the road's effect on Huntley Meadows. Much of the road would be elevated to permit water to flow through the park, Alexander said. County plans call for periodic monitoring of the animal and plant life near the road as well as the water level near Dogue Creek, which drains into the park.

The county expects traffic noise to reach "significant" or "severe" levels along the roadway if nearby commercial and residential development takes place over the next 10 years. The county plans to monitor noise levels.

Jose Garza came to the hike with his wife Nohemi and 12-year-old daughter Julia. They live 2 1/2 blocks from the park.

"We're concerned about the impact on the neighborhood. It would increase the flow of traffic. It will increase the noise substantially," Jose Garza said. "I would rather put in the 10-minute drive than lose what we have in the park," he said, referring to the time he might save if the road is installed.

A 45-mph speed limit is planned, and there is a possibility that truck traffic would be limited, according to current plans.

"I was instrumental in getting Huntley Meadows dedicated to the county. I won't do anything to harm that piece of property," Alexander said.

Robert Gift, a National Park Service official for the mid-Atlantic region, said that the county's environmental study was deemed satisfactory after the county agreed to take care of water that would drain from the road into the park.