The 409-acre quarry property makes up most of the land under the park expansion proposal. The rest of the properties are smaller tracts in Virginia, Maryland Heights across the Potomac River in Maryland, and along the intersection of U.S. 340 and Millville Road, including where the Harpers Ferry Flea Market operates.
The plan also would help preserve the view from Jefferson Rock, where Thomas Jefferson stood on Oct. 25, 1783, and marveled at the natural surroundings.
"Most people assume that is protected," Rosa said. "It is not."
Rosa and others interested in preserving the sites want Congress to pass legislation allowing the park's boundary to expand and to obtain funding to purchase the tracts.
Whether or not landowners want to sell would be up to them, Rosa said.
There was mixed reaction from the commission on the idea.
Commissioner Rusty Morgan said not enough is known about the plan, and he bristled at an attempt by Commissioner Jim Surkamp to pass a motion in support of the resolution.
"I'm not supporting it," Morgan said of the motion. "You can make it."
"This is a big step without any warning whatsoever," Morgan said.
Commissioner Greg Corliss voted against a decision by the commission not to change the land-use designation to allow the office development project at Old Standard quarry, and said Thursday he still supports development of the property.
Commissioner Dale Manuel said he wanted more time to study an expansion of the park, and the commission later tabled the issue until Sept. 20.
Rosa told the commission that supporters of the park expansion have met with U.S. Rep. Shelley Moore Capito, R-W.Va., U.S. Sen. Jay Rockefeller, D-W.Va., and staff members in the office of U.S. Sen. Robert C. Byrd, D-W.Va., about the plan.
Commission President Frances Morgan was among the people who met with Rockefeller, Rosa said.
The Harpers Ferry Town Council and the Bolivar Town Council support the idea, and Harpers Ferry Mayor Jim Addy stood beside Rosa as he spoke.
Herb Jonkers, one of the developers who proposed the development of the Old Standard quarry, said Thursday he would listen to any offers to buy the quarry property.
But Jonkers said it "just boggles my mind" that county officials do not understand the value of developing the quarry.
"I don't think that's the best use of the property," Jonkers said.
Supporters of the office project said it could generate up to 6,000 new jobs, increase the county's tax base and allow many county residents to work locally rather than commuting to nearby metropolitan areas.
An attorney representing the developers who proposed the office project said he believes the developers have a right to continue a heavy industrial use on the land similar to the quarry operations. Jonkers said he has been in contact with county land planners about what uses are allowed there.
If Harpers Ferry National Historical Park is enlarged, it would be the second expansion since 2004, when the park was expanded by 1,240 acres to a total of 3,745 acres.
Preservation groups and individuals pushed for the park expansion in light of rapid development in the area.