Open Spaces and Mountain Parks - that's the name of Boulder's long-standing program to preserve land around the city, preventing the kind of development that leads to urban sprawl.

The city currently holds 45 thousand acres of land – grasslands, forests, mountains. Some of it serves as wildlife habitat, some is used for agricultural purposes and then, of course, there are all the recreation opportunities. 150 (!) miles of trail crisscross this land, for hiking, horseback riding and biking. That means I barely have to leave my house before I’m smack dab in the middle of some pretty gorgeous places.

While all this is great, I think it’s even more impressive that the whole thing got started over 100 years ago. In 1898, Boulder used revenue from a bond sale to acquire the alfalfa fields and apple orchards that ran along the community's western edge, right up against the Flatiron Mountains (an area that would later become the Chautauqua National Historic Landmark). The government followed that up a few years later with a federal grant of 1600 acres of mountain land. And then the city levied yet another bond to purchase an additional 1200 acres in that same area.

But the big push came when Boulder experienced a massive population surge in the 1950s and 60s. The city more than doubled in size, housing underwent a major boom and the Boulder-Denver turnpike opened – all of that meant the open lands around the city were ripe for further development. Concerned about what this meant, a group of citizens created a group called PLAN Boulder County to campaign for land preservation.

One of their first achievements was the establishment of a “blue line,” which would prevent city water from being supplied above a certain elevation. That would limit development in the mountains' foothills.

Then, in 1964, a luxury developer proposed a fancy-pants hotel on a chunk of land known as the Enchanted Mesa, which overlooked Boulder from the west but activists were able to raise enough money from the community to buy the land.

And then, in 1967, voters approved a sales tax specifically for the purchase, management and maintenance of open spaces. Let me repeat that. They approved a tax ON THEMSELVES to protect the land around them. Pretty cool.

The plan has clearly changed the feel of Boulder, especially in comparison with a lot of other places in the west. Rather than a run-on of cities, one stringing right into the next, or a sprawled out suburban wasteland of big box stores, you drive through rural areas on every side before reaching the actual city. It sets the city apart, gives it a separate identity, makes it accessible and preserves some of its history.

But there’s at least one big downside, namely that it contributes to the high cost of living. Land is at a premium here and housing is expensive – meaning that while a lot of people can come visit (approximately 5.3 million a year access the Open Spaces), it’s only a very small few that can afford to stay.