Sources
Every fact on this site traces to a source. Here is where the numbers and notes come from, and how we compute what we compute.
Land managers & agencies
Bureau of Land Management
Wilderness study areas and public-land status in the San Juans.
blm.gov
US Forest Service
Trailhead pages and recreation info — access, road, and fee details.
fs.usda.gov
Trinchera Blanca Ranch
Access waiver for Mount Lindsey (private land).
mountlindseywaiver.com
National Park Service
Rocky Mountain National Park access, timed-entry, and permits (Longs Peak).
nps.gov
Reference
Wikipedia
Background, history, and general facts, each traced to its own citations.
en.wikipedia.org
Wilderness Connect
The interagency wilderness portal — designated-wilderness boundaries and regulations.
wilderness.net
Historical & primary
USGS Board on Geographic Names
Official summit names and elevations.
d9-wret.s3.us-west-2.amazonaws.com
Library of Congress
Historical survey and first-ascent records.
loc.gov
American Alpine Club
First-ascent history and mountaineering records.
publications.americanalpineclub.org
Western Mining History
Mining-era context for the Mosquito/Tenmile peaks.
westernmininghistory.com
Open data & computed
OpenStreetMap
Trail geometry for the 3D routes and the driving network behind our ballpark drive times.
USGS 3DEP
The elevation model under every terrain render and routed profile.
How we compute things
Distance & elevation gain
Published route figures where a source gives them; otherwise our own line measured over OpenStreetMap trails and the USGS 3DEP elevation model.
Drive times
Ballpark driving time from four Colorado cities, computed once over the OpenStreetMap road network (computed 2026-07-09). Shown rounded with a “~”; tap a maps link for live directions from where you are.
Estimated duration
A rough estimate from distance and gain using Naismith’s rule — named for the Scottish mountaineer William W. Naismith, who proposed it in 1892 — scaled for altitude and rest. A planning aid, not a promise.
Beginner-fit & difficulty
Difficulty is the route’s class. The beginner-fit score is computed from class, gain, distance, and steepness; it does not yet factor access. “Easier” never means easy — conditions decide.
Sourcing policy
Facts trace to government (.gov/.us) or recognized authoritative sources, each with a “checked” date. We don’t cite crowd-sourced trip-report sites; where a fact only appears there, we leave it out.