# Relationship history for MSHA mine 1512781

Current hierarchy: **Hall Jay → Quadrex Inc → 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:** O K Coal Company → No 1 Mine; 1981-03-01 to 1981-10-22; source msha-controller-operator-history
- **controller_controls_mine:** Slater Gary Et Al → No 1 Mine; 1981-03-01 to 1981-10-22; source msha-controller-operator-history
- **controller_controls_operator:** Slater Gary Et Al → O K Coal Company; 1981-03-01 to 1981-10-22; source msha-controller-operator-history
- **operator_operates_mine:** Quadrex Inc → No 1 Mine; 1981-10-23 to 1984-03-18; source msha-controller-operator-history
- **controller_controls_mine:** Blackburn Lawyer → No 1 Mine; 1981-10-23 to 1984-03-18; source msha-controller-operator-history
- **controller_controls_operator:** Blackburn Lawyer → Quadrex Inc; 1981-10-23 to 1984-03-18; source msha-controller-operator-history
- **operator_operates_mine:** Quadrex Inc → No 1 Mine; 1984-03-19 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hall Jay Et Al → No 1 Mine; 1984-03-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hall Jay Et Al → Quadrex Inc; 1984-03-19 to current/open; source msha-controller-operator-history