# Relationship history for MSHA mine 1501737

Current hierarchy: **Mullins Elzy → Robin L Coal Company → No 10 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:** James E Derry et al → No 10 Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Potter Brothers Mining Company Inc → No 10 Mine; 1950-01-01 to 1979-01-23; source msha-controller-operator-history
- **controller_controls_mine:** Potter Reed Sr → No 10 Mine; 1950-01-01 to 1979-01-23; source msha-controller-operator-history
- **controller_controls_operator:** Potter Reed Sr → Potter Brothers Mining Company Inc; 1950-01-01 to 1979-01-23; source msha-controller-operator-history
- **operator_operates_mine:** Bentley & Derry Coal Company Inc → No 10 Mine; 1979-01-24 to 1979-06-04; source msha-controller-operator-history
- **controller_controls_operator:** James E Derry et al → Bentley & Derry Coal Company Inc; 1979-01-24 to 1979-06-04; source msha-controller-operator-history
- **controller_controls_operator:** Michael  Derry et al → Bentley & Derry Coal Company Inc; 1979-01-24 to 1979-06-04; source msha-controller-operator-history
- **operator_operates_mine:** Robin L Coal Company → No 10 Mine; 1979-06-05 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mullins Elzy → No 10 Mine; 1979-06-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mullins Elzy → Robin L Coal Company; 1979-06-05 to current/open; source msha-controller-operator-history