Know your data sources.

Oklahoma Commissioners of the Land Office state-trust real estate + mineral leases. SCOOP/STACK parallel. No auth. - searchLeases ⭐ category=real-estate (default, ~2.9K) | mineral (~4.5K, activeOnly default true) - getExpiringLeases ⭐ defaults to curated Expiring Real Estate Leases layer (~580) - getLeaseDetail, searchWellInventory (OCC mirror, ~576K), getServiceInfo upstream quirks: BeginDate/EndDate are ISO YYYY-MM-DD strings (server-side date filters work). CountyName UPPERCASE upstream. Mineral layer mixes ACTIVE + EXPIRED — use activeOnly=true (default). LeaseType values on Real Estate: Agricultural / Short-term Commercial / Long-term Commercial.

Oklahoma DEQ wellhead protection + remediation + monitoring. Native ArcGIS REST MapServers, no auth. - searchWellheadProtectionAreas ⭐ — drilling-restriction polygons (~5.9K) around PWS - searchRemediationSites ⭐ — Institutional Controls (~890) under formal cleanup programs - searchVoluntaryCleanupSites, searchAccreditedLabs (~151), searchAirQualitySites (28) - getServiceInfo quirks: WHPA has NO name / county / facility id — only ZONE (A/B/C) + SOURCE_IND. Filter zone or bbox. Remediation County values dirty (Garfeld vs Garfield, "Tulsa" vs "Tulsa County") — handler LIKE-matches + Title-Case strips trailing " County". LabAccred Lab_Type has typos. Base_Certification_Status always 'Accredited'. Air POLLUTANTS comma-joined; LIKE-matched.

Oklahoma Water Resources Board aquifers + floodplains + biological data. Native ArcGIS REST + AGOL Feature Services (owner: OWRBOnline), no auth. - searchAquifers ⭐ — 71 aquifer polys across 4 layers (Major/Minor × Bedrock/Alluvial) - getFloodplain ⭐ — point-in-polygon FEMA SFHA lookup (~23,539 polys) - searchStreamFishCounts (~10,749 obs), getServiceInfo quirks: Aquifers MapServer (csa.ou.edu) uses LOWERCASE field names (name/class/type) vs uppercase on AGOL. Floodplain is OWRB-published from FEMA NFHL — FLD_ZONE in X/AE/A/AO/AH; no name/county column. Stream Fish Counts has no county column — bbox/near is the geo filter; FISH_GROUP is taxonomic family.