Part of what makes Boulder such an appealing place is its natural beauty, and residents of the Boulder area are committed to preserving that beauty. There are a number of green initiatives and conservation and preservation groups in the area, and even the City of Boulder offers a Green Building and Green Points Program.
The Congress of the United States approved the allocation of 1,800 acres of mountain backdrop and watershed area extending from South Boulder Creek to Sunshine Canyon in 1899, and that marked the beginning of government preservation of open space around Boulder.
As the city has grown, Boulder has adopted and implemented a policy of controlled urban expansion. For example, in 1959 city voters approved the "Blue Line" city-charter amendment which restricted city water service to altitudes below 5,750 feet in an effort to protect the beautiful mountain backdrop from development. In 1967, city voters approved a dedicated sales tax for the acquisition of open space in an effort to contain urban sprawl. In 1970, Boulder created a "comprehensive plan" that would dictate future zoning, transportation, and urban-planning decisions. Hoping to preserve residents' views of the mountains, in 1972, the city enacted an ordinance limiting the height of newly constructed buildings.
Prairie dogs, which are considered a keystone species and have long been exterminated by farmers, ranchers, and urban development, are protected in the Boulder area. An Urban Wildlife Management Plan was also created and implemented by the City of Boulder, which sets policies for managing and protecting urban wildlife. The city's parks department has a Conservation Team which monitors parks to protect ecosystems. And occasionally residents find that parks and hiking trails are closed to conserve or restore local ecosystems.
The Center for Resource Conservation and many other similar non-profit organizations call Boulder home. This, combined with Boulder’s historic popularity among hippies and environmentalists, and the presence of Colorado’s largest university, put the city of Boulder at the leading edge of green development, innovations and technology.