Data sources & attribution

OpenStreetMap

Trail geometry, trail and route names, parking areas, summits, viewpoints, water features, roads, place names and administrative boundaries are © OpenStreetMap contributors, available under the Open Database License (ODbL) v1.0.

Our rendered maps and pages are Produced Works under that license. Our own trailhead parking research is a separate dataset and is not derived from OpenStreetMap.

USGS 3D Elevation Program (3DEP)

Trailhead elevations come from the USGS 3DEP point query service. As a work of the United States government it is in the public domain (17 U.S.C. § 105).

Satellite imagery and topo map

The topo view is the USGS topographic base map (contours, names and roads) from the same source. The satellite view shows aerial photography from The National Map (USGS, with imagery from USDA). It is loaded directly from USGS servers while either view is on, and credited in the corner of the map. We have not copied or stored it.

Software

Maps are rendered with MapLibre GL JS (BSD-3-Clause). The site is built with Astro (MIT).

Deliberately not used

We do not serve tiles from OpenStreetMap's own tile servers. Their tile usage policy prohibits the prefetching and offline caching this site is designed around. Our basemap is built from OpenStreetMap data and served from our own infrastructure.

Vermont's state trail layers — VCGI E911 Trails and the 2025 SCORP trails inventory — are not used. Neither publishes a license permitting commercial redistribution.