AT BALTIMORE'S Mount Washington Elementary School this fall, 11-year-old Will Glasgow stays for the sixth grade, a possibility created by a community effort to form a middle school to stem long-standing middle-class flight.

Along North Avenue, developer Wendy Blair briskly sells out Spicer's Run, 86 handsome new brick townhouses that go for as much as $190,000, to unsubsidized buyers who choose city life over the suburbs.

From a station under the Atrium -- pricey apartments carved from the old Hecht's store on Howard Street -- more than 30 police officers, many on bikes, wage quality-of-life battles as the city renews its west side, even issuing citations for public urination.

With such steps and more, Baltimore nibbles at the powerful forces hollowing out the core of this region and state -- taking the city over the last 40 years from 939,000 residents to fewer than 650,000, from 50 percent of the region's population to 25 percent.

Baltimore is the rear flank of sprawl in Maryland, the concentrated disinvestment and problems that low-density suburban development creates and unsuccessfully tries to flee. The well-being of the entire region and state hinges on reversing this.

Right now, the city has only about 30 percent of the region's jobs, down from almost 50 percent 20 years ago. Its median household income hovers at 65 percent of the region's. It has 60 percent of the region's poor people, one-eighth its tax base and more murders some weekends than some nearby counties all year. It offers schools that, though improving, are still suburban real estate agents' best friend.

In the next 20 years or so, another million people will be in Maryland, costing another half-million acres of the state's open land. More effective suburban growth management, restraining sprawl's "pull," is only part of the solution; it can't succeed without an attack on the urban forces pushing sprawl.

As growth engulfs Maryland's suburbs, this linkage becomes ever firmer. Take northern Baltimore County's landmark down-zoning three decades ago: It successfully saved open land by restraining development inside the Beltway and along certain corridors. But, as the city's problems spread to these aging inner suburbs, the county still loses middle-class residents to Carroll and Harford counties.

For even the most distant suburbanite, this is hardly academic: The Baltimore region and Maryland can't prosper with a feeble center hobbling its economy, draining state resources and propelling more sprawl -- driving up taxes, traffic congestion and pollution everywhere else. "As the city goes, so goes Carroll County," says Julia Walsh Gouge, recently re-elected county commissioner there. "People don't make the correlation. Everybody is just working their own turf, and when you only consider your own turf, we all lose."

In 1995, urbanologist David Rusk concluded Baltimore -- with its vast needs and weak tax base -- had reached "the point of no return," arguing for regional tax sharing. These days, such regionalism engenders no political support, while Baltimore still suffers by Mr. Rusk's measures.

But bright spots give hope. Baltimore's population and job losses are slowing, its school test scores are rising sharply, and its per capita income keeps pace by growing relatively faster. Average city housing prices are rising by at least 15 percent annually, as the waterfront boom moves inland. There are new drives to market Baltimore to Washingtonians, support its healthy neighborhoods, and identify among the city's 14,000 abandoned houses those that could be rehabbed or cleared for redevelopment. The massive west-side redevelopment project and plans for an east-side biotech park bode the restoration of greater economic mass, thereby countering sprawl.

"Smart use of city land means a smart use of land elsewhere," says local economist Anirban Basu. And right now, city developers say, demand rapidly mounts as aging baby boomers jettison their lawns for the city, joining their echo-boom offspring. The ultimate challenge is building a market among families with school-age children.

Impossible? In Middle River, the now-cleared site of the Riverdale Apartments -- once Baltimore County's roughest complex and as troubled as many city areas -- offers a glimpse. There, the first of 175 suburban-style homes are selling without subsidy for as much as $250,000, some to families from Harford and other suburbs. As available land dries up in suburbia, suburban developer Larry Rosenberg now sees big opportunities inside and along the city's Beltway: "People didn't want to leave this area. There was nothing for them. ... If you have something for them, it'll bring people back."

Nothing about this is easy or cheap. To foster such market-rate development, the city needs a renewed and costly state commitment: more money to acquire and clear land, to repair sewers and other aged infrastructure, for more crime control and drug treatment, and, most important, for rebuilding schools.

For Gov.-elect Robert L. Ehrlich Jr. and his successors, this may be the most vexing long-term conundrum: Elected by suburban voters around Baltimore and central Maryland, Mr. Ehrlich can't improve their lives if he ignores the growing need for wise reinvestment in the city. With Maryland's huge projected budget deficit, that might seem unaffordable right now -- but in the long run, it's the cheapest and only sustainable path for the entire region and state.

Tomorrow: Transit