# Relationship history for MSHA mine 1510332

Current hierarchy: **Simmons Harold D → S S C Mining Inc → No 6 Surface 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:** Simmons Harold D → No 6 Surface Mine; 1975-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Franklin Charles K → No 6 Surface Mine; 1975-04-25 to 1979-04-19; source msha-controller-operator-history
- **operator_operates_mine:** Hardy Coal Company Inc → No 6 Surface Mine; 1977-03-01 to 1979-04-19; source msha-controller-operator-history
- **controller_controls_operator:** Franklin Charles K → Hardy Coal Company Inc; 1977-03-01 to 1979-04-19; source msha-controller-operator-history
- **operator_operates_mine:** S S C Mining Inc → No 6 Surface Mine; 1979-04-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Simmons Harold D → S S C Mining Inc; 1979-04-20 to current/open; source msha-controller-operator-history