Trails feature class from the USGS National Transportation Dataset (NTD), which is part of the USGS National Map. Version 10.1.
The USGS Transportation downloadable data
from The National Map (TNM) is based on TIGER/Line data provided through
U.S. Census Bureau and supplemented with HERE road data to create tile
cache base maps. Some of the TIGER/Line data includes limited
corrections done by USGS. Transportation data consists of roads,
railroads, trails, airports, and other features associated with the
transport of people or commerce. The data include the name or route
designator, classification, and location. Transportation data support
general mapping and geographic information system technology analysis
for applications such as traffic safety, congestion mitigation, disaster
planning, and emergency response. The National Map transportation data
is commonly combined with other data themes, such as boundaries,
elevation, hydrography, and structures, to produce general reference
base maps. The National Map viewer allows free downloads of public
domain transportation data in either Esri File Geodatabase or Shapefile
formats. For additional information on the transportation data model, go
to http://nationalmap.gov/transport.html.