# Relationship history for MSHA mine 1517671

Current hierarchy: **Thomas L  Kemp → Mid-South Stone Quarry Inc → Mid-South Stone**

- 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:** Mid-South Stone Quarry Inc → Mid-South Stone; 1995-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Thomas L  Kemp et al → Mid-South Stone; 1995-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thomas L  Kemp et al → Mid-South Stone Quarry Inc; 1995-05-01 to current/open; source msha-controller-operator-history