# Relationship history for MSHA mine 1510647

Current hierarchy: **Little Maurice → Red Dog Coal Company 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:** Ajax Mines Inc → No 1 Mine; 1977-08-01 to 1978-09-12; source msha-controller-operator-history
- **controller_controls_mine:** Tackett Stanford → No 1 Mine; 1977-08-01 to 1978-09-12; source msha-controller-operator-history
- **controller_controls_operator:** Tackett Stanford → Ajax Mines Inc; 1977-08-01 to 1978-09-12; source msha-controller-operator-history
- **operator_operates_mine:** Sandy Ryan Coal Company → No 1 Mine; 1978-09-13 to 1979-11-04; source msha-controller-operator-history
- **controller_controls_mine:** Johns Barry Et Al → No 1 Mine; 1978-09-13 to 1979-11-04; source msha-controller-operator-history
- **controller_controls_operator:** Johns Barry Et Al → Sandy Ryan Coal Company; 1978-09-13 to 1979-11-04; source msha-controller-operator-history
- **operator_operates_mine:** Red Dog Coal Company Inc → No 1 Mine; 1979-11-05 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Little Maurice → No 1 Mine; 1979-11-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Little Maurice → Red Dog Coal Company Inc; 1979-11-05 to current/open; source msha-controller-operator-history