The city consulted with urban planners as far back as 1904, resulting in the development of Washington Park and the 40-Mile Loop greenway, which interconnects many of the city's parks. Portland is often cited as an example of a city with strong land use planning controls. This is largely the result of statewide land conservation policies adopted in 1973 under Governor Tom McCall, in particular the requirement for an urban growth boundary (UGB) for every city and metropolitan area. The opposite extreme, a city with few or no controls, is typically illustrated by Houston.