# Relationship history for MSHA mine 1516389

Current hierarchy: **Bartley Keith → Maxton Corp → Maxton #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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Maxton Corp → Maxton #1 Surface; 1988-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bartley Keith → Maxton #1 Surface; 1988-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bartley Keith → Maxton Corp; 1988-05-01 to current/open; source msha-controller-operator-history