Illinois State Geological Survey (ISGS) ILOIL well registry plus oil/gas/storage field polygons and waterflood-area boundaries via maps.isgs.illinois.edu. - searchWells ⭐ ~207K wells with API, status code+text, operator, formation, depth - searchOilGasFields ⭐ ~1K canonical 2024 unified oil + gas + gas-storage polygons (or ~550 legacy) - getWellByApi single well lookup, searchWaterfloodAreas, getServiceInfo §0 spec drift: brief listed Oil_Gas_GasStor_Fields_2023 — that service is 404. Canonical service is _2024. Wells layer is at index 8 of Wells/MapServer (NOT 0). STATUS column has 100+ codes; STATUS_TEXT has 100+ descriptive variants. Legacy service uses upper-snake fields, 2024 uses camelCase. Native CRS 102100; outSR=4326.
5 methodsFreshness not declared
