More than 100 turned out for a planned rally at the Reston National Golf Course Sunday against the development of the 166 acres which has long been kept as natural open space.

The group, which calls itself “Rescue Reston,” says the acreage is “Certified Audubon Cooperative Sanctuary Program Golf,” and that its designation as open space dates back to Reston founder Bob Simon’s vision for the community.

“We’re going to send a message to the majority owner of the golf course — Northwestern Mutual — and potential bidders that Reston will not stop defending the 166 acres across Sunrise Valley Drive from the Northwestern Mutual offices,” said Connie Hartke, president of Rescue Reston. “Restonians have the power when the zoning is already on our side.”

“[Our] message to speculators regarding the sale of Reston National Golf Course is: buy a golf course if you wish, but know that recreational open space is all you will have,” Hartke continued.

News of this latest potential sale and development of Reston National Golf Course emerged earlier this year when ARA Newmark began distributing information that implies the acreage is “coming soon” for interested parties. The memorandum indicates it was prepared “solely for the use of prospective buyers of the real property commonly known as Reston National Golf Course.”

Rescue Reston members have been consulting with attorneys in preparation of fighting any potential rezoning, sale or development of the property, the organization’s website states.