Gaithersburg and Rockville are both trying to claim part of Shady Grove Road. And whoever gets there first wins.

The border dispute started when Gaithersburg announced plans to annex 27.9 acres along Shady Grove Road just north of Frederick Road/Route 355, including 13.7 acres owned by Sears and the road used to reach it.

Though Sears closed the Great Indoors, its home-improvement showcase center there, the company plans to continue using the space for retail and offices, according to the annexation application that the company filed with Gaithersburg. The plans required a zoning change, and getting a change is easier if the property is within Gaithersburg's city limits.

But Rockville officials say Gaithersburg's plans infringe on the historic border between the two cities.

Although the property lies in both cities' maximum allowable limits, Shady Grove Road has served as a boundary between them, with Gaithersburg's border to the northwest and Rockville's to the southeast. This was part of "an unwritten understanding," and was part of the basis for a Memorandum of Understanding signed in 1992, said Rockville Mayor Phyllis Marcuccio.

Now, Rockville is trying to annex the road between Gaithersburg's current borders and the Sears property, effectively cutting Sears off so that Gaitherburg's city limits and the proposed addition are no longer contiguous.

"These properties have had Gaithersburg ZIP codes since the early '60s," said Gaithersburg Community Planning Director Trudy Schwarz.

If Rockville succeeds, Gaithersburg's plans would have been foiled. But if Gaithersburg approves its changes first, Rockville will have to change course since both cities can't claim the same land.

"There's a certain amount of flexing of muscles here," said Montgomery County Councilwoman Nancy Floreen, D-at large, and chairwoman of the council's Planning, Housing and Economic Development Committee. "They're trying to cut off Gaithersburg at the pass."

Any change would not technically affect any private properties, only the road itself, said Rockville Chief of Long Range Planning David Levy, who added that visitors to the Sears property can't get there without driving outside the Gaithersburg city limits.

The fight is going to come down to whomever approves the annexation first, said Glenn Kreger, chief of the county's Area 2 Planning Division. "I haven't seen a battle like this in the time that I've worked for the Planning Department, which is over 20 years now."

The Montgomery County Council is scheduled to vote Tuesday on Gaithersburg's zoning change, which has been recommended by both the county Planning Board and Floreen's committee. Gaithersburg's City Council and mayor will likely take it up after that.

The Rockville City Council and mayor are scheduled to take up the issue Sept. 10.