# Relationship history for MSHA mine 2302475

Current hierarchy: **Mark  Magruder → Magruder Limestone Company, Inc. → IROCK PORT #2**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Mark  Magruder → IROCK PORT #2; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Magruder Limestone Company, Inc. → IROCK PORT #2; 2014-06-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mark  Magruder → Magruder Limestone Company, Inc.; 2014-06-10 to current/open; source msha-controller-operator-history