Transparency

Where the data comes from.

We use official government sources only. We do not scrape commercial property sites, and we do not buy repackaged data when the authoritative source is public. Every dataset below was tested directly against its live service before we built on it.

Official Montana data sources, checked regularly and automatically.

An automated monitor probes each authoritative source daily and triggers a full synchronization when records change. Most recent successful check: September 28, 2026 at 1:49 PM (Mountain).

Montana Bureau of Mines and Geology, Ground Water Information Center (GWIC)

Verified 2026-08-13

Montana Bureau of Mines and Geology (MBMG), Montana Tech

Visit source

22 layers, capabilities Query,Extract, no authentication. 330,777 well sites verified by exact count query.

Access method: https://mbmgmap.mtech.edu/server/rest/services/Water_Resources/GWIC_Database/FeatureServer
Upstream update cadence: Static water level layer updates daily (latest observed measurement 2026-08-12). Core well records updated on an ongoing basis; no published schedule.
Our source-check schedule: daily
Last successful source check: Sep 28, 2026
Last retrieved: September 26, 2026

Montana Department of Natural Resources and Conservation (DNRC), Water Rights Bureau

Verified 2026-08-13

Montana DNRC

Visit source

Layer 0 = Points of Diversion (point). Layer 1 = LLD Places of Use (polygon).

Access method: https://gis.dnrc.mt.gov/arcgis/rest/services/WRD/WMB_WaterRightsData/FeatureServer
Upstream update cadence: Continuous administrative updates as rights are filed, amended, and adjudicated.
Our source-check schedule: daily
Last successful source check: Sep 28, 2026
Last retrieved: August 14, 2026

Montana State Library, Montana Cadastral Framework

Verified 2026-08-13

Montana State Library

Visit source

Layer 1 = Montana Parcels. Native spatial reference is wkid 6514 (Montana State Plane); must request outSR=4326.

Access method: https://services.arcgis.com/qnjIrwR8z5Izc0ij/ArcGIS/rest/services/Montana_Cadastral_Framework/FeatureServer
Upstream update cadence: Parcel attributes are annual tax-year snapshots (TaxYear field); geometry maintained continuously by counties.
Our source-check schedule: daily
Last successful source check: Sep 28, 2026
Last retrieved: August 14, 2026

Montana DNRC, Water Resources Division

Verified 2026-08-13

Montana DNRC

Visit source

Layer 11 = Controlled Groundwater Areas (21 features). Layer 12 = Closures (182 features). Layer 13 = Dewatered Streams.

Access method: https://gis.dnrc.mt.gov/arcgis/rest/services/WRD/WRD/MapServer
Upstream update cadence: Changes only by DNRC order or legislative action; infrequent.
Our source-check schedule: monthly
Last successful source check: —
Last retrieved: September 26, 2026

Montana DNRC, Water Management Bureau — Source Aquifer Codes

Verified 2026-08-13

Montana DNRC

Visit source

Layer 11 = statewide aquifer polygons with hydrogeologic descriptions.

Access method: https://gis.dnrc.mt.gov/arcgis/rest/services/WRD/WMB_AquiferSourceCodes/MapServer
Upstream update cadence: Static reference layer; revised rarely.
Our source-check schedule: monthly
Last successful source check: —
Last retrieved: September 26, 2026

Montana DNRC — Statewide Aquifer Properties

Verified 2026-08-13

Montana DNRC

Visit source

Layer 1 = point-level aquifer tests with transmissivity, storativity, and PDF reports.

Access method: https://gis.dnrc.mt.gov/arcgis/rest/services/WRD/WMB_MontanaAquiferTests/MapServer
Upstream update cadence: Appended as new aquifer tests are submitted and reviewed.
Our source-check schedule: monthly
Last successful source check: —
Last retrieved: Not yet loaded

U.S. Geological Survey, Water Data for the Nation

Verified 2026-08-13

USGS

Visit source

Phase 3. Use collections/field-measurements with parameter_code=72019 (depth to water below land surface).

Access method: https://api.waterdata.usgs.gov/ogcapi/v0
Upstream update cadence: Continuous. Legacy NWIS gwlevels API decommissioned 2025-11-01.
Our source-check schedule: weekly
Last successful source check: —
Last retrieved: Not yet loaded

EPA / USGS Water Quality Portal

Verified 2026-08-13

U.S. EPA and USGS

Visit source

Phase 3. Montana well results verified: 54,487 specific conductance; 47,920 pH; 38,952 TDS; 10,912 nitrate; 7,739 arsenic. Use mimeType=csv (JSON returns 406) and siteType=Well.

Access method: https://www.waterqualitydata.us/data
Upstream update cadence: Continuous contribution by federal, state, and tribal organizations.
Our source-check schedule: monthly
Last successful source check: Sep 28, 2026
Last retrieved: September 26, 2026

Montana DEQ, Petroleum Tank Cleanup — tank substance releases

Verified 2026-09-13

Montana Department of Environmental Quality, Waste Management & Remediation Division

Visit source

Environmental screening, category 1. 4,519 documented petroleum releases statewide on the verification date (824 open, 3,669 resolved). Status is DEQ's own: Open / Reopened / Resolved. Rescinded determinations are excluded because they are not releases. Street addresses are borrowed from the matching DEQ facility record or the same release in EPA UST Finder; the site point is DEQ's.

Access method: https://gis.mtdeq.us/hosting/rest/services/Hosted/Montana_Tank_Substance_Releases_/FeatureServer/0
Upstream update cadence: Continuous; the layer's last-edit stamp moves as DEQ staff update release records.
Our source-check schedule: daily
Last successful source check: Sep 28, 2026
Last retrieved: September 26, 2026

EPA Superfund Enterprise Management System (SEMS) — Montana sites

Verified 2026-09-13

U.S. Environmental Protection Agency

Visit source

Environmental screening, category 2. 124 Superfund-program sites in Montana on the verification date, 19 of them on the final National Priorities List. Each record links to EPA's own site page.

Access method: https://services.arcgis.com/cJ9YHowT8TU7DUyn/arcgis/rest/services/FRS_INTERESTS_SEMS/FeatureServer/0
Upstream update cadence: Weekly refresh of the EPA Facility Registry Service extract.
Our source-check schedule: daily
Last successful source check: Sep 28, 2026
Last retrieved: September 26, 2026

EPA UST Finder — registered underground storage tank facilities

Verified 2026-09-13

U.S. Environmental Protection Agency, Office of Research and Development

Visit source

Environmental screening, context layer. 6,137 registered tank facilities in Montana, current and historical. A registered tank is not a release; this layer never changes the screening result and is shown for context only.

Access method: https://services.arcgis.com/cJ9YHowT8TU7DUyn/arcgis/rest/services/UST_Finder_Feature_Layer_2/FeatureServer/0
Upstream update cadence: Periodic, from state program data supplied to EPA.
Our source-check schedule: daily
Last successful source check: Sep 28, 2026
Last retrieved: September 26, 2026

How we treat these sources

We consume official APIs and ArcGIS services rather than scraping pages, and we ingest on a schedule into our own normalized database instead of calling state servers on every user request.
We rate-limit our ingestion deliberately. These are small agency servers, and the whole product depends on not overloading them.
Every record we store keeps its source dataset, source URL, and retrieval timestamp, which is what lets a report cite its own figures.
Reports are frozen snapshots. A report you bought last month still shows the data as it stood when you bought it, with its own vintage stamp.
We attribute all sources and we do not represent government data as our own. Our contribution is the normalization, the comparable-well methodology, and the analysis.

Read how we turn these datasets into a report