# Relationship history for MSHA mine 4001624

Current hierarchy: **Blankenship Albert E → Par Coal Company → No 2 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:** S & S Coal Company → No 2 Mine; 1974-09-01 to 1976-06-27; source msha-controller-operator-history
- **controller_controls_mine:** Sharp John L & Leon Savage → No 2 Mine; 1974-09-01 to 1976-06-27; source msha-controller-operator-history
- **controller_controls_operator:** Sharp John L & Leon Savage → S & S Coal Company; 1974-09-01 to 1976-06-27; source msha-controller-operator-history
- **controller_controls_mine:** Blankenship Albert E → No 2 Mine; 1976-04-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** B & W Coal Company → No 2 Mine; 1976-06-28 to 1977-03-02; source msha-controller-operator-history
- **controller_controls_mine:** Bruce Herman & James Wilson → No 2 Mine; 1976-06-28 to 1977-03-02; source msha-controller-operator-history
- **controller_controls_operator:** Bruce Herman & James Wilson → B & W Coal Company; 1976-06-28 to 1977-03-02; source msha-controller-operator-history
- **operator_operates_mine:** Par Coal Company → No 2 Mine; 1977-03-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Blankenship Albert E → Par Coal Company; 1977-03-03 to current/open; source msha-controller-operator-history