Mobil Corp. helped put Fairfax County on the map for corporate America in 1980 when it relocated the headquarters of its domestic refining and marketing operations to a woodsy campus at the intersection of the Capital Beltway and Route 50.

Hilton Hotels, Volkswagen of America and Northrop Grumman eventually followed suit, and this year, 10 Fairfax County-based companies made the Fortune 500.

Now Fairfax County and its economic development unit are facing a new problem: what to do when the corporate pioneer — one of its chief tax benefactors — moves elsewhere.

Exxon Mobil, Mobil Corp.’s parent since 1999, has decided to relocate its Fairfax County operations, consisting of about 2,100 jobs, to Houston. Executives hope to have the campus completely vacated by the end of 2015.

Since deciding to depart, Exxon Mobil and its real estate consultants have been showing local officials and interested parties around their campus and this week are formally putting the property up for sale.

The exterior of the main building at Exxon Mobil’s 117-acre campus in Merrifield, which is now up for sale as it prepares to relocate to Houston. Exxon Mobil’s secluded campus is one of the most valuable properties in Fairfax County. (Courtesy Exxon Mobil)

Though it is bordered by the Beltway, Gallows Road and Route 50, the campus is cloaked on all sides by trees, secluding it from surrounding neighborhoods. Of the 117 acres, 92 remain in their natural state.

In the center are four connected office buildings built in two phases, one in 1979 and the other in 1989, plus a services building. Though the offices, which total 1.2 million square feet, don’t feature the floor-to-ceiling glass and 360-degree views that newer buildings might, there are many features that corporate users typically appreciate. Among them: more than 60 conference rooms, nine-foot ceilings, a 736-seat cafeteria, a gym, a swimming pool and a corporate board room featuring a lustrous beech wood table.

Discretion and security were obviously priorities in constructing it. Buried underground are more than 90 percent of Exxon Mobil’s 2,580 parking spaces and a quarter-mile-long service tunnel where all deliveries arrive.

Exxon Mobil and its real estate advisers from Cassidy Turley have branded the property One Fairfax. “We think this is one of the most attractive properties not only in the Washington, D.C., area, but that there’s very few things like this in the entire U.S.,” said Mark J. Stachowiak, portfolio manager for global real estate and facilities at Exxon Mobil.

A range of buyers might be interested in the property, and a handful have come forward already, according to Stachowiak and Gerald L. Gordon, executive director of the Fairfax County Economic Development Authority. “I think you could see anything from another corporate user, or corporate users plural, to any other kinds of uses,” Gordon said. “We won’t really know until they get the responses.”

The site has been talked about as a possible landing place for the FBI, as it fits the parameters of the agency’s headquarters search. But keeping the property on the tax rolls is a priority for Gordon. It is among the most valuable properties in the county, assessed this year at $201.3 million, which equates to a 2013 property tax bill of nearly $2.2 million. “We don’t want to lose them off the tax base,” Gordon said.

If the county cannot reel in another corporate titan to take over the campus, Exxon may sell to a developer, which could set up a battle for zoning changes. Two additional offices totaling 550,000 square feet have already been approved, but Exxon Mobil is also floating a concept that would more than double the density on the property.

Fairfax County Supervisor ­Linda Q. Smyth (D-Providence District), whose district includes the Exxon campus, said zoning changes were not ideal and would require changing the area’s comprehensive plan.

“I think what people need to keep in mind is that they need to work with the site as it is, with the limited access and with the things that go with the site, as opposed to try to reinvent the site,” Smyth said. “I mean, it’s hard to reinvent geography.”

Stachowiak said the way the campus is used will be up to its new owner. “We’re not a developer. Any further development is between the new buyer, whoever that is, and the county,” he said.

Attracting another major corporate user, a skill for which Gordon has gained a reputation, might lessen the likelihood of a contentious zoning proposal. “Modern corporations are comprised of people and people have different tastes,” Gordon said. “Somewhere there is somebody who will like it.”