# Relationship history for MSHA mine 3607243

Current hierarchy: **Deeter Gary L & John Koperna → K & D Coal Company → Skidmore Slope**

- 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

- **operator_operates_mine:** Ferndale Coal Company → Skidmore Slope; 1981-12-01 to 1984-11-13; source msha-controller-operator-history
- **controller_controls_mine:** Tetkoskie Daniel L → Skidmore Slope; 1981-12-01 to 1984-11-13; source msha-controller-operator-history
- **controller_controls_operator:** Tetkoskie Daniel L → Ferndale Coal Company; 1981-12-01 to 1984-11-13; source msha-controller-operator-history
- **operator_operates_mine:** M & S Coal Company → Skidmore Slope; 1984-11-14 to 1985-06-04; source msha-controller-operator-history
- **controller_controls_mine:** Murin Joseph G Et Al → Skidmore Slope; 1984-11-14 to 1985-06-04; source msha-controller-operator-history
- **controller_controls_operator:** Murin Joseph G Et Al → M & S Coal Company; 1984-11-14 to 1985-06-04; source msha-controller-operator-history
- **operator_operates_mine:** K & D Coal Company → Skidmore Slope; 1985-06-05 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Deeter Gary L & John Koperna → Skidmore Slope; 1985-06-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Deeter Gary L & John Koperna → K & D Coal Company; 1985-06-05 to current/open; source msha-controller-operator-history