# Relationship history for MSHA mine 1512617

Current hierarchy: **Sexton Willis → Briar 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

- **controller_controls_mine:** Randy A  Cook et al → No 2 Mine; 1975-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Cesco Coal Company Inc → No 2 Mine; 1980-11-01 to 1981-10-29; source msha-controller-operator-history
- **controller_controls_operator:** Randy A  Cook et al → Cesco Coal Company Inc; 1980-11-01 to 1981-10-29; source msha-controller-operator-history
- **controller_controls_operator:** Michael K  Cook et al → Cesco Coal Company Inc; 1980-11-01 to 1981-10-29; source msha-controller-operator-history
- **operator_operates_mine:** Briar Coal Company → No 2 Mine; 1981-10-30 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Sexton Willis → No 2 Mine; 1981-10-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sexton Willis → Briar Coal Company; 1981-10-30 to current/open; source msha-controller-operator-history