# Relationship history for MSHA mine 1512951

Current hierarchy: **Maynard John → S A M Construction Company Inc → No 1 Surface Mine (D)**

- 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:** S A M Construction Company Inc → No 1 Surface Mine (D); 1981-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Maynard John → No 1 Surface Mine (D); 1981-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Maynard John → S A M Construction Company Inc; 1981-06-01 to current/open; source msha-controller-operator-history