# Relationship history for MSHA mine 1512780

Current hierarchy: **Adams John M → Adam'S Construction Company → 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:** A & A Construction Company → No 1 Surface; 1981-03-01 to 1982-05-26; source msha-controller-operator-history
- **controller_controls_mine:** Anderson Donald Et Al → No 1 Surface; 1981-03-01 to 1982-05-26; source msha-controller-operator-history
- **controller_controls_operator:** Anderson Donald Et Al → A & A Construction Company; 1981-03-01 to 1982-05-26; source msha-controller-operator-history
- **operator_operates_mine:** Adam'S Construction Company → No 1 Surface; 1982-05-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Adams John M Et Al → No 1 Surface; 1982-05-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Adams John M Et Al → Adam'S Construction Company; 1982-05-27 to current/open; source msha-controller-operator-history