Connie Melvin thought she had found her private eden when she and her husband moved to this rural community of 1,200 after years of suburban living in Howard County's new town of Columbia.

Deer and pheasant walked across their three-acre lot and their front view was of an old farm and green cornfields. "There were lots of us from Silver Spring, Laurel and even Columbia who moved out here because we wanted a rural setting, a lovely spot for our families," Melvin said.

Today, with Columbia's developers poised to expand the town west and south toward Clarksville, Melvin's vision of a peaceful farming community has given way to thoughts of high-density housing at her doorstep on Rte. 32.

Howard Research and Development (HRD), which developed Columbia 16 years ago, has already invested $200 million for a 1,750-acre "village" that would include as many as 3,380 new homes.

For two hours tonight a polite but cool audience of housewives, Clarksville farmers and residents of exclusive Trotter Road near Columbia jammed a county meeting room as one of HRD's top urban designers described the plan for Columbia's final phase.

"You might not necessarily agree with this plan, but we ask that you keep your mind open about it," said Al Scavo, who heads the HRD design team for the Trotter Road Village. "The unknown is the worst of all, not only to you but also to us."

Scavo answered repeated and sometimes pointed questions about the company's plans to build moderate- or high-density housing on the rolling fields and thick forests that line Middle Patuxent River between Columbia and Clarksville. HRD has asked the county's planning board to change a "new town" zoning designation to allow the construction of apartments and town houses in the final village.

If the zoning change is approved, HRD could earmark as many as 141 acres of land now zoned for single-family houses for denser construction.

"With higher density housing we would lose the rural character of this neighborhood," said Frank B. Cockrell, a Beltsville resident who maintains a 99-acre farm off Rte. 108 near the proposed village site. Cockrell, a U.S. Fish and Wildlife Service employe, said apartments and town houses would "threaten Clarksville, which is really a buffer between Columbia and western Maryland.

"This town's beauty is what brings people to Clarksville," said Cockrell, "and who knows what the environmental impact a project this size would have?"

Connie Melvin, who is organizing a citizens' association to fight HRD's zoning change request, said she and her neighbors were "absolutely beside ourselves . . . The low density was one of the big reasons we moved here in the first place," Melvin said. "Now we come to find out that whole way of life may go down the tube."

Scavo said it would probably be several years before construction of the new Columbia village begins, and at least 20 years before all work is completed. "In something like this, he said, you're not going to satisfy 100 percent of the people . . . . Of course they'd like to see nothing happen to that land and I don't blame them.

"But it's our property, our investment. We're not the ogre."