# Relationship history for MSHA mine 1510617

Current hierarchy: **Stewart Paul → Horizon Coal Inc → No 1 Surface**

- 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:** Horizon Coal Inc → No 1 Surface; 1977-08-01 to 1979-04-23; source msha-controller-operator-history
- **controller_controls_mine:** Carson Donald → No 1 Surface; 1977-08-01 to 1979-04-23; source msha-controller-operator-history
- **controller_controls_operator:** Carson Donald → Horizon Coal Inc; 1977-08-01 to 1979-04-23; source msha-controller-operator-history
- **operator_operates_mine:** Horizon Coal Inc → No 1 Surface; 1979-04-24 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Stewart Paul → No 1 Surface; 1979-04-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Stewart Paul → Horizon Coal Inc; 1979-04-24 to current/open; source msha-controller-operator-history