# Relationship history for MSHA mine 4606509

Current hierarchy: **Westmoreland Coal Company → Elk River Sewell Coal Company → Powell Fork Surface Mine**

- 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:** Poval Corporation → Powell Fork Surface Mine; 1979-10-17 to 1984-12-20; source msha-controller-operator-history
- **operator_operates_mine:** We Coal Inc → Powell Fork Surface Mine; 1982-04-01 to 1982-09-06; source msha-controller-operator-history
- **controller_controls_mine:** Patterson W L → Powell Fork Surface Mine; 1982-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Patterson W L → We Coal Inc; 1982-04-01 to 1982-09-06; source msha-controller-operator-history
- **operator_operates_mine:** Elk River Sewell Coal Company → Powell Fork Surface Mine; 1982-09-07 to 1984-12-19; source msha-controller-operator-history
- **controller_controls_operator:** Poval Corporation → Elk River Sewell Coal Company; 1982-09-07 to 1984-12-19; source msha-controller-operator-history
- **controller_controls_mine:** Hawkins Denver A Et Al → Powell Fork Surface Mine; 1984-05-08 to 1987-08-23; source msha-controller-operator-history
- **operator_operates_mine:** M & H Coal Company Inc → Powell Fork Surface Mine; 1984-12-20 to 1987-08-23; source msha-controller-operator-history
- **controller_controls_operator:** Hawkins Denver A Et Al → M & H Coal Company Inc; 1984-12-20 to 1987-08-23; source msha-controller-operator-history
- **controller_controls_mine:** Westmoreland Coal Company → Powell Fork Surface Mine; 1984-12-21 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Elk River Sewell Coal Company → Powell Fork Surface Mine; 1987-08-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Westmoreland Coal Company → Elk River Sewell Coal Company; 1987-08-24 to current/open; source msha-controller-operator-history