Sources & methodology

Every major map family has a destination.

“Live” means the browser can currently request vector features. “ETL-ready” means the source is resolved to real GIS but belongs in the normalized tile pipeline before it should be turned on as a large web layer. The complete machine-readable manifest is also available as raw source catalog JSON.

Layer family	Status	Publisher / source	Why it is handled this way
Current visitor map geometry	live	National Park Service / ArcGIS Online	Primary runtime source is the public visitor web map when readable. If it fails, the tool can fall back to a public 2021 Isle Royale FeatureServer with POIs, trails, and park boundary before using approximate local anchors. Current closures, regulations, transportation, and campground status always hand off to current NPS pages.
Visitor map fallback item	fallback	National Park Service / ArcGIS Online	Secondary public web map item. If both web-map items fail, a public 2021 FeatureServer is tried before any approximate local anchors.
Regional access and transportation map	cataloged	National Park Service	Use as a planning/reference source; operational transportation information must be verified against current NPS and operators.
Rock Harbor area guide	cataloged	National Park Service	Direct NPS Rock Harbor Area Guide (2015). Use for facility/orientation context; current operational status still comes from current NPS pages.
Windigo area guide	cataloged	National Park Service	Direct NPS Windigo Area Guide (2015). Use for facility/orientation context; current operational status still comes from current NPS pages.
Off-trail camping zones	current-status-plus-reference	National Park Service	Isle Royale uses 46 off-trail camping zones on the permit map. Current closure zone numbers are parsed from the NPS Current Conditions feed and surfaced as operational status without inventing polygon geometry; verify the current permit map and conditions before departure.
Ferry, seaplane and water access	runtime-plus-reference	National Park Service	Public web-map routes may render at runtime; current schedules remain external operational data.
Shipwrecks and current dive buoys	live-api	National Park Service	current NPS scuba page / downloadable buoy dataset. Runtime discovers the current NPS Shipwreck Buoys sortable dataset, maps only rows with parseable NPS buoy GPS coordinates, and retains depth/vessel/buoy details in the maritime layer. Buoys and dive conditions can change; verify NPS before diving.
USGS shaded relief / terrain	live-tile	U.S. Geological Survey	USGS The National Map shaded relief; data refreshed April 2025. Keyless cached relief overlay derived from 3DEP at larger scales and GMTED2010 at smaller scales. Used as an optional terrain context layer, not as navigation data.
Isle Royale lighthouses	runtime-plus-reference	National Park Service	Four lighthouse locations; current access restrictions must come from current NPS information.
Geology	research-only	National Park Service Geologic Resources Inventory	NPS GRI digital release 2021; older source mapping. Generated from the NPS GRI GeoPackage: 1,975 geologic-unit features, reprojected and simplified for web use. Manifest records SHA-256 and source accuracy caveat; not survey-grade. Retained in the source/research catalog but intentionally removed from the trip-planning layer controls because it does not improve route decisions.
Vegetation baseline (2000)	research-only	National Park Service	2000 inventory; imagery primarily 1994/1996. Historical baseline only. The 19,072 source polygons are dissolved into 38 TNC_DESCRI vegetation classes and simplified for opt-in web display. Do not interpret as current forest condition. Retained in the source/research catalog but intentionally removed from the trip-planning layer controls because it does not improve route decisions.
Vegetation overview (2000) — 6 broad classes	research-only	Derived from NPS vegetation inventory	Derived overview of the 2000 NPS vegetation inventory; imagery primarily 1994/1996. Six visitor-facing classes derived from the verified detailed NPS inventory, dissolved by broad family and simplified for web orientation. Historical baseline only, not current vegetation. Retained in the source/research catalog but intentionally removed from the trip-planning layer controls because it does not improve route decisions.
Quiet / No-Wake zones — 22 official polygons	generated-runtime	National Park Service	Official NPS DataStore Collection 9705; 22 per-zone GeoJSON files validated against the 2026 Superintendent's Compendium. The 22 official NPS zone files are assembled one-zone-per-file. Mott, Rock Harbor/Snug Harbor, and Washington Harbor are classified as the three No-Wake zones from the current compendium; the remaining 19 are Quiet/No-Wake zones.
Anchorage zones	cataloged	National Park Service	Direct NPS Anchorage Zones map (2018), retained as an official boating-planning reference. Verify current restrictions and conditions before acting.
Archived brochure map	reference-only	National Park Service; discovered via NPMaps	Historical/reference layer only. Never present old route or regulation information as current.
Historic Windigo Nature Trail map	reference-only	National Park Service; discovered via NPMaps	Date-stamp and keep disabled by default if later georeferenced.
Boat-in campground facilities	live-api	National Park Service	page updated June 23, 2026. Fetched through the same-origin Isle Royale API and matched to mapped campgrounds by normalized public place name. Includes dock depth, shelters, tent sites, food lockers, stay limit, fire/grill and generator fields when NPS supplies them.
Current Isle Royale conditions and closures	live-api	National Park Service	Fetched through the same-origin Isle Royale API. The tool detects only closure patterns it knows how to parse and never treats a no-match result as proof that the park has no alerts.
Vegetation change, 1996–2017	research-only	U.S. Geological Survey	2017 high-resolution imagery compared with the 2000 NPS vegetation map (1994/1996 imagery). Shows mapped vegetation cover type, density or pattern change and proposed reasons from the USGS release; not a present-day 2026 vegetation map. Retained in the source/research catalog but intentionally removed from the trip-planning layer controls because it does not improve route decisions.
2021 Horne Fire burn severity	research-only	U.S. Geological Survey	2021 Horne Fire; USGS data release published 2024. Burn-severity assessment derived from pre/post-fire high-resolution imagery; use as historical ecological context, not a current fire-status layer. Retained in the source/research catalog but intentionally removed from the trip-planning layer controls because it does not improve route decisions.