City of Portland

In 2003 Portland Parks & Recreation staff began inventorying ecological conditions within the city's natural areas. All field survey data is organized in relation to specific geographic boundaries called Vegetation Units as represented in this layer. Initial mapping of Vegetation Unit boundaries is done by visual interpretation of orthophotos. During subsequent field surveys boundaries are modified so that Vegetation Units represent areas of homogenous vegetative and ecological conditions.

Desired future conditions for natural areas owned by, managed by, or in collaboration with Portland Parks & Recreation's City Nature program. Areas are generally classified by plant association and ecological system as organized in the National Vegetation Classification System.

This dataset represents proposed and existing trail centerlines within the general vicinity of Portland, Oregon.

It is an amalgamation of many different sources compiled at many different scales.