# Relationship history for MSHA mine 3608004

Current hierarchy: **Crispen Howard D & Edward L → Crispen Contracting Company → Stewart Est**

- 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:** Crispen Contracting Company → Stewart Est; 1988-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Crispen Howard D & Edward L → Stewart Est; 1988-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Crispen Howard D & Edward L → Crispen Contracting Company; 1988-03-01 to current/open; source msha-controller-operator-history