# Relationship history for MSHA mine 1501197

Current hierarchy: **Adams David Lee & Judy Adams → David Lee Adams 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Verlin Bailey Coal Company → No 1 Mine; 1950-01-01 to 1973-01-14; source msha-controller-operator-history
- **controller_controls_mine:** Bailey Verlin Coal Company → No 1 Mine; 1950-01-01 to 1974-02-11; source msha-controller-operator-history
- **controller_controls_operator:** Bailey Verlin Coal Company → Verlin Bailey Coal Company; 1950-01-01 to 1973-01-14; source msha-controller-operator-history
- **operator_operates_mine:** Ben Sproles Coal Co → No 1 Mine; 1973-01-15 to 1973-09-06; source msha-controller-operator-history
- **controller_controls_mine:** Sproles Ben Et Al → No 1 Mine; 1973-01-15 to 1974-10-14; source msha-controller-operator-history
- **controller_controls_operator:** Sproles Ben Et Al → Ben Sproles Coal Co; 1973-01-15 to 1973-09-06; source msha-controller-operator-history
- **operator_operates_mine:** Madeline Coal Co → No 1 Mine; 1973-09-07 to 1974-05-01; source msha-controller-operator-history
- **controller_controls_mine:** Madeline Coal Company → No 1 Mine; 1973-09-07 to 1974-05-01; source msha-controller-operator-history
- **controller_controls_operator:** Madeline Coal Company → Madeline Coal Co; 1973-09-07 to 1974-05-01; source msha-controller-operator-history
- **operator_operates_mine:** David Lee Adams Coal Company Inc → No 1 Mine; 1974-05-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Adams David Lee & Judy Adams → No 1 Mine; 1974-05-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Adams David Lee & Judy Adams → David Lee Adams Coal Company Inc; 1974-05-02 to current/open; source msha-controller-operator-history