Ian Kennedy stood at the lectern, waiting for his turn to speak to the Howard County Council. Although he's a jacket-and-tie guy by day, last Thursday night he was wearing a green T-shirt with the message, "Save Merriweather Post."

For Kennedy, 27, who grew up in Columbia going to concerts at Merriweather Post Pavilion, saving the amphitheater has become a second career. When he isn't at his desk at the Maryland Department of Natural Resources, he and friend Justin Carlson, founders of Save Merriweather, attend public meetings. They have been to at least 14 in the past few months -- including one Zoning Board session that lasted until 4 a.m. -- spreading the word that the amphitheater's future is uncertain.

"We feel that Merriweather is one of the symbols of Columbia, a defining characteristic that makes our planned community unique," said Kennedy, who with Carlson, 29, has created a Web site, passed out fliers, had T-shirts printed and gradually built a broad network of supporters in Columbia and beyond for the concert hall James Rouse built in 1967.

As the Rouse Co. prepares to finalize the firm's sale to General Growth Properties Inc., a key piece of unfinished business has prompted widespread community concern. Rouse has put Merriweather Post up for sale, giving Howard County first rights to buy. But there is one caveat: Rouse is insisting that any buyer transform Merriweather into a much smaller, enclosed hall with far less parking.

If that happens, Maryland would lose its only outdoor concert venue. That would leave Wolf Trap and Nissan Pavilion in Northern Virginia and the smaller Carter Barron Amphitheatre in the District for large outdoor concerts in the region.

"My counterparts across the state would sell their souls to have something like this in their communities. It is a regional gem," said Rachelina Bonacci, head of Howard's tourism office. "And here in Howard County, we may tear it down."

In the short run, one more season for Merriweather seems likely. Late last week, Rouse notified the amphitheater's operator, I.M.P. Inc. of Bethesda, that it will lease Merriweather to the company for next year's season.

Still, Rouse officials say attendance has been declining for years at Merriweather, which can accommodate up to 19,000 people and is best known for large rock concerts. But the county has "matured" beyond the musical fare at Merriweather, said Dennis W. Miller, a Rouse vice president in charge of the company's Columbia property.

"We don't see its offerings as aligning with the population of Howard County," he said.

Howard is the nation's second most affluent county, the Census Bureau reported recently, with a median household income of $88,555. But that doesn't mean the community doesn't like rock-and-roll or a night of mellow music under the stars, Save Merriweather organizers say.

Last week, several members of a panel -- from business, the arts, government and education -- appointed by County Executive James N. Robey (D) to examine Rouse's offer appeared to agree that Merriweather should remain an outdoor venue. The panelists also began discussing the possibility of a year-round performing arts space on the 10.8 acres surrounding the pavilion, off Little Patuxent Parkway across from the Mall in Columbia. With a children's theater and classrooms, it could be similar to the facilities at the federally owned Wolf Trap in Vienna.

Meanwhile, I.M.P. disputes Rouse's assertion that the amphitheater is in decline and says Merriweather is winding up a robust season this year.

"When the Rouse Company says the place loses money, I don't know where they get that," said Jean Parker, Merriweather's general manager.

Although attendance and revenues were down in recent seasons, this year has been much better, Parker and I.M.P. Chairman Seth Hurwitz said. Hurwitz and partner Rich Heinecke took over the operations at Merriweather this year from Clear Channel Entertainment, which manages competitor Nissan Pavilion near Manassas in Prince William County.

The season, which ends next month, has included at least two sellout events and has attracted concertgoers from well beyond Howard County, Parker said. A recent market analysis showed that this year about 8 percent of tickets were bought by local residents, 60 percent from elsewhere in Maryland and 32 percent from out of state.

Regardless of how much money the pavilion makes, it undoubtedly is worth more to Rouse if it's sold and developed, members of the community panel said.

I.M.P. pays about $500,000 in rent annually, according to information the company provided to the county panel. The same property, were it developed commercially or with housing, could net the company tens of millions of dollars, according to estimates from several local officials. Rouse is said to be asking for about $6 million for the Merriweather property, which is assessed at $4.2 million.

Some community leaders and local officials say Rouse's real motivation for wanting to sell Merriweather is its plans to develop a 63-acre parcel, known as the Crescent property, around it.

Earlier this year the county Zoning Board rejected the company's proposal to develop housing on that site. Tuesday the Howard County Planning Board is expected to give preliminary approval to Rouse's proposal to develop up to 1.2 million square feet of commercial space there, including possible big box stores. As part of the development, Rouse wants land now used for parking at Merriweather.

If Merriweather continues as a large, outdoor music venue, with occasionally noisy concerts and lots of traffic, it might not be the ideal neighbor for a commercial or residential development. Miller says the prospective sale of Merriweather and the plans to develop the adjacent site are unrelated.

Robey's panel is worried that a smaller, indoor venue, with or without parking, simply might not be viable. Toby Orenstein, founder of Toby's Dinner Theatre and a longtime fixture in the Howard County arts community, warns, "Keep in mind that Strathmore Hall in Rockville in Montgomery County cost $100 million."

That hall, plagued with cost overruns that ended up costing Montgomery County and the state millions, is soon to open and will have about 2,000 seats, similar to what Rouse has proposed for Merriweather. And both Strathmore and Merriweather are relatively close to the Clarice Smith Performing Arts Center at the University of Maryland, which has been generously subsidized by the state.

Within a few miles of Merriweather Post, Howard Community College is building a performing arts center partly funded with Rouse donations. There is also the Jim Rouse Theatre for Performing Arts at nearby Wilde Lake High School.

The proposed sale of Merriweather and the plan to develop the neighboring parcel come at what might be a critical juncture in Columbia's growth. With little land left to develop, county officials are taking a closer look at the future of Columbia's downtown, or Town Center.

County Council member and Zoning Board Chairman Ken Ulman (D-West Columbia) and council President Guy Guzzone (D-Southeast County) say they hope to see the property around Merriweather turned into Columbia's "Central Park," with more sidewalks, possibly pedestrian bridges and other amenities.

Many suggested that the Merriweather property, with its canopy of trees in the heart of Columbia's commercial center, could become a focal point for that type of development.

"We can see that the Crescent provides a tremendous opportunity to accomplish something truly unique . . . something that will restore Columbia's status as one of the most forward thinking communities in the country," said Kennedy, of Save Merriweather.

Merriweather Post Pavilion, which can accommodate up to 19,000 people, is best known for large rock concerts, including, clockwise from above, performances by Jimmy Buffett, Britney Spears and the Cure's Robert Smith. Above, members of a panel studying Rouse's offer to sell Merriweather to the county tour the facility. Below left, I.M.P. Chairman Seth Hurwitz speaks to the group about the venue. Below right, Justin Carlson, a founder of Save Merriweather. "When the Rouse Company says the place loses money, I don't know where they get that," said Jean Parker, Merriweather's general manager, above. She said this season has included at least two sellout events. Below, Seth Hurwitz talks with Dennis W. Miller, right, a Rouse vice president in charge of the company's Columbia property. I.M.P. pays Rouse about $500,000 a year in rent.