Greg Glenn has a pasture at Rocklands Farm in Poolesville, Md. Glenn's farm is only about 20 minutes from the beltway, and it's in what's known as the Agreserve. It's a broad section of Montgomery County -- about one-third of it -- that's off limits to dense development.
"People are buying fresh, buying local, people want organic, sustainable. There's incredible demand for this kind of stuff," he says. "What the reserve has to offer is that it's so close. Not only do you get your food picked that day or get delivered, but you can easily after work get in your car and visit that farm."
The reserve was created in 1980, at a time when suburban sprawl was just starting to fragment farming communities.
"Farms were being chopped up," says Callum Murray, a planner with Montgomery County's Planning Department.
He says the idea to limit development in 93,000 acres was more than just a way to keep farms intact; it was a way to prevent sprawl.
"There was a certain fiscal logic to this because it limited the extension of infrastructure, it limited leapfrog development patterns, and it limited roads water and sewer extension, and it limited problems for school boards and emergency services," Murray says.
And he says it's worked.
"There's a clear edge where the reserve stops and starts," Murray says. "If you imagined the pattern of development we have down county, spread across the whole county, I think we'd have a megalopolis with the traffic congestion far worse."
One of the major ways the county has limited development in the reserve has been through something called transferrable development rights. For example, if a developer wants to build a high-rise in Rockville, that developer has to buy that right from a farmer in the reserve. A farmer can get tens of thousands of dollars this way, but can't use his or her land for anything but agriculture, ever.
Around 75 percent of the reserve is protected by some type of easement like this. Ben Alnutt runs Homestead Farm in the reserve. His family's been farming this area for almost 300 years. He says while the easement restrictions are protecting agriculture, the irony is that they're also limiting it.
"Someone wants to build a grain elevator. Well that's pretty much agricultural, but that's not allowed because of the way the laws are written," he says.
Alnutt also points out a challenge for attracting more small farmers: "We have all this agricultural land. Where are all the farmers gonna live?"
Dividing lots is difficult where it is allowed, and outside of the reserve there's only about 4 percent of the county's land that's vacant, with 300,000 more people expected to arrive over the next 20 years. Already, half of people who work in Montgomery County commute in from elsewhere, says Steve Fuller, an economist at George Mason's Center for Regional Analysis.
"Restricting areas to low-density housing or agricultural uses will become a much more serious constraint 10, 15 years from now," he says.
Jim Cohen, director of the Urban Studies and Planning Program at the University of Maryland, he says there are indeed tradeoffs.
"There are costs, things you are sacrificing when you preserve that land that way, and one of those purposes is housing," he says.
But Cohen says the county has plenty of other tools at its disposal to provide housing.
"We shouldn't just look at that reserve as the only supply of land that the county has for increased housing production," he says.
There are rules that require 15 percent of any new housing development to include affordable housing. And increasingly the county is looking to build up rather than out. Murray, with the Planning Department, says that with the right management, the county is far from filling up.
"If you look at Manhattan or Hong Kong, we have a long ways to go," Cohen says.
And he says there are few New Yorkers who begrudge the existence of Central Park.