{"data":{"schemaVersion":"realm.temporal-relationships.v1","temporalSemantics":{"validTime":{"granularity":"date","bounds":"inclusive","nullStart":"start date not published in the upstream history row","nullEnd":"open-ended in the upstream history row; not independent proof of present control"},"transactionTime":{"observedAt":"2026-10-18T09:31:49.615908+00:00","meaning":"time the checksum-addressed MDRS artifacts were observed by the PostgreSQL ingestion"},"derivation":{"controllerControlsOperator":"intersection of controller and operator valid-time intervals evidenced through this mine","currentIdentity":"current controller and operator are asserted only by the MDRS Mines snapshot"}},"current":{"mine":{"type":"mine","id":"2302278","name":"Hermann Sand-Jefferson City Plant"},"operator":{"type":"operator","id":"L34218","name":"Hermann Sand & Gravel Inc"},"controller":{"type":"controller","id":"M34218","name":"Steven W  Engemann"},"source":{"datasetId":"msha-mines","observedAt":"2026-10-18T09:31:49.615908+00:00"}},"edges":[{"type":"controller_controls_mine","subject":{"type":"controller","id":"M34218","name":"Steven W  Engemann"},"object":{"type":"mine","id":"2302278","name":"Hermann Sand-Jefferson City Plant"},"validFrom":"1950-01-01","validTo":null,"current":true,"derived":false,"source":{"datasetId":"msha-controller-operator-history","observedAt":"2026-10-18T09:31:49.615908+00:00","recordKey":"2302278|M34218|1950-01-01|"}},{"type":"controller_controls_mine","subject":{"type":"controller","id":"M36548","name":"Gregory J Muenks et al"},"object":{"type":"mine","id":"2302278","name":"Hermann Sand-Jefferson City Plant"},"validFrom":"1990-02-01","validTo":null,"current":true,"derived":false,"source":{"datasetId":"msha-controller-operator-history","observedAt":"2026-10-18T09:31:49.615908+00:00","recordKey":"2302278|M36548|1990-02-01|"}},{"type":"operator_operates_mine","subject":{"type":"operator","id":"L36548","name":"Muenks Brothers Quarries Inc"},"object":{"type":"mine","id":"2302278","name":"Hermann Sand-Jefferson City Plant"},"validFrom":"2003-02-10","validTo":"2008-08-05","current":false,"derived":false,"source":{"datasetId":"msha-controller-operator-history","observedAt":"2026-10-18T09:31:49.615908+00:00","recordKey":"2302278|L36548|2003-02-10|2008-08-05"}},{"type":"controller_controls_operator","subject":{"type":"controller","id":"M36548","name":"Gregory J Muenks et al"},"object":{"type":"operator","id":"L36548","name":"Muenks Brothers Quarries Inc"},"validFrom":"2003-02-10","validTo":"2008-08-05","current":false,"derived":true,"evidenceMineId":"2302278","intervalAnomaly":false,"source":{"datasetId":"msha-controller-operator-history","observedAt":"2026-10-18T09:31:49.615908+00:00","recordKey":"2302278|L36548|2003-02-10|M36548|1990-02-01|165702"}},{"type":"operator_operates_mine","subject":{"type":"operator","id":"L34218","name":"Hermann Sand & Gravel Inc"},"object":{"type":"mine","id":"2302278","name":"Hermann Sand-Jefferson City Plant"},"validFrom":"2008-08-06","validTo":null,"current":true,"derived":false,"source":{"datasetId":"msha-controller-operator-history","observedAt":"2026-10-18T09:31:49.615908+00:00","recordKey":"2302278|L34218|2008-08-06|"}},{"type":"controller_controls_operator","subject":{"type":"controller","id":"M34218","name":"Steven W  Engemann"},"object":{"type":"operator","id":"L34218","name":"Hermann Sand & Gravel Inc"},"validFrom":"2008-08-06","validTo":null,"current":true,"derived":true,"evidenceMineId":"2302278","intervalAnomaly":false,"source":{"datasetId":"msha-controller-operator-history","observedAt":"2026-10-18T09:31:49.615908+00:00","recordKey":"2302278|L34218|2008-08-06|M34218|1950-01-01|163003"}}],"coverage":{"historyRecords":2,"edgeCount":6,"intervalAnomalies":0,"sourceDatasetId":"msha-controller-operator-history"}},"meta":{"mineId":"2302278","dataSource":"postgres","snapshotId":"2026-10-18T09:31:49.615908+00:00","completedAt":"2026-10-18T09:31:49.615Z","sourceCount":20,"totalRows":17915666,"relationshipSemantics":"valid time; null validTo means current or open-ended in the source"}}