The number of games played by county residents at Black Rock has increased by about 8 percent to 10 percent over last year, Phillips said.
At the same time, the number of games played by people from outside Washington County has dropped by about 15 percent to 20 percent, he said.
Courses throughout the region are reporting similar declines, he said.
One reason for the decrease is that golfers from larger cities, such as Baltimore and Washington, D.C., who once played at Black Rock are now teeing off at courses closer to home, Phillips said.
A marketing plan would include an advertising campaign that probably would call for placing more ads in metropolitan newspapers, he said.
The City of Hagerstown plans to develop its own marketing plan for the city-owned Municipal Golf Course, said Public Information Manager Karen Giffin.
Information on the plan, which probably will include an advertising campaign, won't be available until this fall, she said.
Due to differences between the county's course and the nine-hole city course, Giffin said she did not think a joint marketing campaign would work.
Other government-owned golf courses do marketing campaigns, County Administrator Rodney Shoop said.
"We were the unusual ones in not going to a marketing plan before this," he said.
A marketing plan makes sense because "you want an asset like that to be used as much as possible," Shoop said.
Dick Schultz, head pro at the privately owned Beaver Creek Country Creek golf course, said he had no problem with a Black Rock marketing campaign.
"We have a good product here. They have a choice where they want to go," he said.