# Relationship history for MSHA mine 0800900

Current hierarchy: **Theurer John → M K J Corp → Grassy Key Pit**

- 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:** Cothron Alonzo → Grassy Key Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Alonzo Cothron Inc → Grassy Key Pit; 1978-03-09 to 1985-06-04; source msha-controller-operator-history
- **controller_controls_operator:** Cothron Alonzo → Alonzo Cothron Inc; 1978-03-09 to 1985-06-04; source msha-controller-operator-history
- **operator_operates_mine:** M K J Corp → Grassy Key Pit; 1985-06-05 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Theurer John → Grassy Key Pit; 1985-06-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Theurer John → M K J Corp; 1985-06-05 to current/open; source msha-controller-operator-history