Data & methods
Every fact on this site is bounded to one named published source and its date. Missing values are unpublished, never zero, and no composite score, rating, or ranking is ever derived across sources. Each family below states its publisher, method and scope, coverage, retrieval date, and what a missing record means.
Current sources
Aquatic invasive species occurrences
- Publisher: Wisconsin Department of Natural Resources
- Method and scope: Public AIS occurrence inventory; non-exhaustive.
- Coverage: 1,701 lakes
- Retrieved: Retrieval date unavailable
- Missing records: No record is not evidence of absence; no-longer-observed never erases a verified occurrence.
Canonical detailed lake dataset (summary-failure fallback)
- Publisher: Wisconsin Department of Natural Resources
- Method and scope: Full detailed per-lake dataset; the browser fetches it only as the summary-failure fallback.
- Coverage: 9,924 detailed records
- Retrieved: Retrieval date unavailable
- Missing records: Same directory/lake-page semantics as the summary corpus.
Compact filter index (projection)
- Publisher: Projected from the governed evidence artifacts
- Method and scope: Per-lake filter facts projected from the published evidence artifacts; availability hints only for detail families.
- Coverage: 9,907 lakes
- Retrieved: Retrieval date unavailable
- Missing records: Absence of a field means the underlying family has no record — never a negative finding.
Development-density proxies (NLCD + Census)
- Publisher: USGS Annual NLCD and US Census Bureau
- Method and scope: Shoreline-ring land-cover and housing-allocation proxies.
- Coverage: 9,924 lakes
- Retrieved: 2026-07-27
- Missing records: Proxies with per-metric source years — never dwelling counts or a score.
Field-measured Secchi clarity (WQP/CLMN)
- Publisher: Water Quality Portal / Citizen Lake Monitoring Network
- Method and scope: Summer field Secchi summaries; a separate method from the satellite estimate.
- Coverage: 1,110 lakes
- Retrieved: 2026-07-20
- Missing records: Absence means no qualifying summer Secchi summary; bottom-limited medians are lower bounds and stay disclosed.
Fish abundance (DNR lake pages)
- Publisher: Wisconsin Department of Natural Resources
- Method and scope: Lakes with a published DNR fish-frequency table.
- Coverage: 4,884 of 9,924 lakes
- Retrieved: 2026-08-04
- Missing records: Absence of a lake means no published DNR fish-frequency table — never a statement about fish presence.
Fish stocking events
- Publisher: Wisconsin Department of Natural Resources
- Method and scope: Stocking events from the DNR stocking database, joined into the lake directory records.
- Coverage: 1,837 of 9,924 lakes with stocking events
- Effective: 1972 to 2024
- Retrieved: Retrieval date unavailable
- Missing records: Event history; a lake without events has no stocking record, never "never stocked".
Fisheries adult population estimates
- Publisher: Wisconsin Department of Natural Resources
- Method and scope: Published adult population estimates for supported species.
- Coverage: 412 lakes
- Retrieved: 2026-07-20
- Missing records: Historical observations, never rankings; absence means no supported public estimate.
Fishing limits (adopted DNR ruleset cycle)
- Publisher: Wisconsin Department of Natural Resources
- Method and scope: Normalized per-lake regulation rows from the adopted DNR ruleset cycle.
- Coverage: 9,921 lakes
- Effective: 2026-03-14 to 2027-03-07
- Retrieved: 2026-08-04
- Missing records: Reviewed current-cycle snapshot: source text stays authoritative and water-specific exceptions apply; verify current DNR regulations before fishing.
Governed species vocabulary
- Publisher: Wisconsin Department of Natural Resources
- Method and scope: The canonical species/regulation group names; filter vocabulary only.
- Coverage: 23 governed names
- Retrieved: Retrieval date unavailable
- Missing records: An empty index disables species filters; never a fish-presence claim.
Lake directory (names, counties, size, depth, access flags)
- Publisher: Wisconsin Department of Natural Resources
- Method and scope: All canonical Wisconsin lake records from the DNR lake directory and lake pages.
- Coverage: 9,924 lake records
- Retrieved: Retrieval date unavailable
- Missing records: Published directory facts; Yes/No access flags are explicit source values, and a missing optional field is unknown, never a negative finding.
Lake shoreline geometry (DNR 24K hydrography)
- Publisher: Wisconsin Department of Natural Resources
- Method and scope: Reviewed shoreline polygons delivered per lake on demand.
- Coverage: 9,317 lakes
- Retrieved: 2026-07-15
- Missing records: Withheld geometry means pending review, never a missing lake.
Managed public land proximity
- Publisher: Wisconsin DNR parcels and USGS PAD-US 4.1
- Method and scope: Calculated proximity, kept separate from the DNR lake-page fact.
- Coverage: 9,924 lakes
- Retrieved: 2026-07-21
- Missing records: Computed context; the published lake-page fact is never overwritten.
Public boat access and shore fishing sites
- Publisher: Wisconsin Department of Natural Resources
- Method and scope: DNR access inventory associated to lakes by reviewed name-and-County matching with a governed distance tie-break; the source publishes no WBIC.
- Coverage: 1,551 lakes with 2,116 associated sites; 3,023 statewide points
- Retrieved: 2026-07-15
- Missing records: A missing association is unknown, never evidence a lake lacks access; withheld associations stay statewide-only.
Original source Original source Original source
Road proximity/density (Census TIGER/Line)
- Publisher: US Census Bureau
- Method and scope: Straight-line geographic context only; never travel time or solitude.
- Coverage: 9,924 lakes
- Observed: 2025
- Retrieved: 2026-07-26
- Missing records: A missing enrichment renders nothing, never "no road".
Runtime source catalog (this catalog)
- Publisher: Generated from the governed canonical artifacts
- Method and scope: One generated entry per runtime source family: basis, temporal status, dates, permissions, and qualification allowlists.
- Coverage: 22 source families
- Retrieved: Retrieval date unavailable
- Missing records: Presentation metadata only — it carries family facts about sources, never lake facts, and its absence withholds nothing except catalog-backed source lines.
Satellite water clarity (Landsat estimate)
- Publisher: Wisconsin Department of Natural Resources
- Method and scope: Landsat-derived clarity estimates, 1999–2017 observation window.
- Coverage: 7,574 lakes
- Effective: 1999 to 2017
- Retrieved: 2026-07-16
- Missing records: Absence means no accepted satellite estimate; never a clarity claim.
Selected-lake profile shards (projection)
- Publisher: Projected from the governed evidence artifacts
- Method and scope: Bounded per-lake projection of the six detail families, loaded on selection.
- Coverage: 9,378 lake profiles
- Retrieved: Retrieval date unavailable
- Missing records: A missing family means no reviewed profile row; never a negative finding.
Trophy/special designations
- Publisher: Wisconsin Department of Natural Resources
- Method and scope: ORW/ERW, Quality Fishing Waters, sensitive areas, and musky categories, each source-scoped.
- Coverage: 6,978 lakes
- Retrieved: 2026-07-28
- Missing records: Independent designations; no generic special-lake flag, and the 2018 musky angling classes stay historical.
USFS recreation facilities (Chequamegon-Nicolet)
- Publisher: US Forest Service Enterprise Data Warehouse
- Method and scope: Constructed USFS recreation sites within 15 km; absence never means "no facilities".
- Coverage: 2,250 lakes
- Retrieved: 2026-07-28
- Missing records: Inventory existence, not open status; area-scoped assertions stay labeled area-scoped.
Wisconsin origin reference points (Census Gazetteer)
- Publisher: US Census Bureau
- Method and scope: Cities, villages, and CDPs (2025 Gazetteer places), active towns (2025 Gazetteer county subdivisions), and ZIP Code Tabulation Area reference points associated to Wisconsin counties by the 2020 relationship file. Distances computed from these points are straight-line to the lake’s published coordinate.
- Coverage: 2,829 origin reference points (804 places, 1,242 towns, 783 ZCTAs)
- Retrieved: 2026-08-09
- Missing records: Each record is the source-published Census internal/reference point — a ZCTA is an approximate ZIP-area reference point, not a USPS ZIP centroid or an exact address; absence of a community means the governed source lists none.
Historical sources
Depth-map links (historical DNR lake maps)
- Publisher: Wisconsin Department of Natural Resources
- Method and scope: Verified links to historical lake-map PDFs; not for navigation.
- Coverage: 2,565 lakes
- Observed: 2026-07-16
- Retrieved: 2026-07-16
- Missing records: Availability of a historical map link only; maps are undated surveys.
Search interpretation
The main search applies only deterministic, supported interpretations. A bare number that is a canonical WBIC is always a lake identity, never a ZIP-area point; lake names containing numbers stay ordinary names. Negated criteria ("no musky", "no carry-in access") are refused with an explanation rather than guessed: the public inventories cannot prove absence. Crowd and quietness phrases apply no filter — no crowd data exists. Phrases like "zebra mussels have not been detected" are likewise refused: absence of an occurrence record is never evidence of absence.
Distance from a place
Origins come from the US Census Bureau: 2025 Gazetteer places (cities, villages, and census-designated places), active towns from the 2025 Gazetteer county subdivisions, and ZIP Code Tabulation Area reference points associated to Wisconsin counties by the 2020 relationship file. A ZCTA is an approximate ZIP-area reference point — not a USPS ZIP centroid and not an exact address. Every distance is a straight-line (great-circle) measurement from the Census-published reference point to the lake's published coordinate; it is never travel time, road distance, or the distance to an access point. Radius filters offer a reviewed set of 25, 50, or 100 miles. Only the stable Census identifier and the chosen radius are stored in links — never typed text or coordinates.
Map coordinate review
Published coordinates pass a reviewed statewide bounds gate before a lake is mapped. Records failing the gate (32 at the current baseline, kept as known issues pending an authoritative correction) remain fully searchable with complete report pages; only their map placement is withheld.
Lake report maps
Eligible lake reports add a collapsed inline map only after JavaScript validates the report WBIC and reviewed coordinate. Opening it starts a governed lightweight report renderer, then loads the content-hashed lake outline and the same selected-lake access-evidence shard used by the textual access disclosure. A missing or failed outline falls back to the reviewed lake location. Markers include only reviewed or qualified lake-associated access records with mappable coordinates; the text list remains authoritative, and no published record never means no public access. External tiles begin only after activation, receive an origin-only referrer, and carry no WBIC, filter state, or telemetry value. The main discovery map continues to use Leaflet; the bounded report renderer is report-only.
The same catalog is published machine-readable at /data/source_catalog.json.