Bellevue Farms, a 1,500-acre Warrenton area estate dating back to the early part of the 18th century, is being developed as a rural residential community with sites ranging from 10 to 30 acres.

Gordon H. Marks, one of the seven developers of the property, and his wife live in the old manor house, which they have fixed up as a home and sales office.

The other general partners in the development are Gerald T. Halpin, C. B. Ewing Jr., T. F. Nicholson, Rudolph Seeley, John Watkins and Kathryn Maclane. All are officers or employees of Westgate Corp., developer of office parks in the Tysons Corner area.

Seeley -- whose dairy farm became major parts of Westgate and Westpark some years ago -- was one of the first to build a new home at Bellevue Farms. eral years ago by the general partners, has been under development for a year. MArks said that 48 of the 85 building sites have been sold (at an average of about $3,000 an acre) and a dozen homes have been completed and another dozen are under construction.

Meanwhile, 200 to 400 head of commercial beef cattle are usually grazing on the site, where a large hay crop is harvested annually, Marks said. The developers operate the cattle farm and consider it an attraction for prospective buyers.

Until the Depression, the farm was owned by the Payne family, of which Robin Marks (wife of Gordon) is a relative. The acreage had changed hands a number of times since then.

The houses, including cost of the lots, range in price from $75,000 to $200,000.