Advocates for Rosa Bonheur Memorial Park in Elkridge have lost the battle over development rights there, but they say the war is not over.

They plan to hold a rally at 2 p.m. Sunday, Oct. 13, at the 78-year-old cemetery on U.S. 1 to draw attention to their argument that graves of pets and people there should not be disturbed.

"The whole point of the rally is to bring attention to the plight of the cemetery," said Candy Warden, president of the Rosa Bonheur Society. The volunteer group takes care of the nearly 8-acre grounds, resting place for the remains of some 28 people and thousands of animals, including a few four-legged celebrities, including the Baltimore zoo's first elephant and mascot dogs for the former Washington Bullets, among others.

The park opened in 1935, and made national news in 1979 as it became what was believed to be the country's first pet cemetery to also allow human burials.

In the culmination of the yearlong process of countywide rezoning, the County Council voted this summer on requests to change zoning on about 200 pieces of land, some next to each other.

The council voted over the objections of Warden's group and others, who sent a couple dozen letters and emails. One woman told how she owns a plot at Rosa Bonheur — which has been closed to new burials since 2003 — and plans to be buried there alongside her mother and her family dogs.

The developer, Donald R. Reuwer Jr., said he wants to leave the graves alone and use about six acres of the cemetery as part of his plan for a more than 21-acre combination of homes and stores. The land lies just south of Route 100 and north of 175 on U.S. 1, a major thoroughfare that has been targeted in the county's master plan for redevelopment.

"We hope to land a great grocery store," Reuwer said in an email. "We do plan on a 50-50 mix of residential and commercial."

A principal in Land Design & Development Inc. of Ellicott City, Reuwer reaffirmed his intention to work with Warden's group to protect the buried remains.

"I'd like to work with the cemetery folks to develop something we can both be proud of. … I am sure they can work with us to create a win-win situation," he said.

In a Sept. 25 letter to County Councilman Calvin Ball, Reuwer said his firm would improve the condition of the cemetery, treat remains with respect and rebury them, when necessary, in another spot on the grounds.

State and county law spell out a process for moving human remains, but no such legal requirements exist for animals. According to the Maryland Office of Cemetery Oversight, Rosa Bonheur is classified as a pet cemetery.

Rosa Bonheur advocates have said they're skeptical about how the land can be developed while still respecting the sanctity of the graves.

"I don't think it can be done," said Barbara Sieg, who has been active in efforts to protect local cemeteries for more than 20 years. "Some people who have pets there or relatives there are going to be anguished."

This story has been updated to note the size of the overall development proposal and how much of the cemetery may be used.

arthur.hirsch@baltsun.com