# Relationship history for MSHA mine 1508378

Current hierarchy: **Bowman Earnest & Roger → B & B Coal Company → No 1 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

- **operator_operates_mine:** Howard & Johnson Coal Company → No 1 Mine; 1975-01-01 to 1976-09-24; source msha-controller-operator-history
- **controller_controls_mine:** Howard Bob & Ronnie Johnson → No 1 Mine; 1975-01-01 to 1976-09-24; source msha-controller-operator-history
- **controller_controls_operator:** Howard Bob & Ronnie Johnson → Howard & Johnson Coal Company; 1975-01-01 to 1976-09-24; source msha-controller-operator-history
- **operator_operates_mine:** Woods Fuel Company → No 1 Mine; 1976-09-25 to 1984-05-23; source msha-controller-operator-history
- **controller_controls_mine:** Howard Grant F → No 1 Mine; 1976-09-25 to 1984-05-23; source msha-controller-operator-history
- **controller_controls_operator:** Howard Grant F → Woods Fuel Company; 1976-09-25 to 1984-05-23; source msha-controller-operator-history
- **operator_operates_mine:** C & M Coal → No 1 Mine; 1984-05-24 to 1986-05-26; source msha-controller-operator-history
- **controller_controls_mine:** Middleton Wendell & Wayne Clem → No 1 Mine; 1984-05-24 to 1986-05-26; source msha-controller-operator-history
- **controller_controls_operator:** Middleton Wendell & Wayne Clem → C & M Coal; 1984-05-24 to 1986-05-26; source msha-controller-operator-history
- **operator_operates_mine:** B & B Coal Company → No 1 Mine; 1986-05-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bowman Earnest & Roger → No 1 Mine; 1986-05-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bowman Earnest & Roger → B & B Coal Company; 1986-05-27 to current/open; source msha-controller-operator-history