# Relationship history for MSHA mine 3101901

Current hierarchy: **Hampton O M → O M Hampton Stone Company → Elk Stone Pit**

- 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:** O M Hampton Stone Company → Elk Stone Pit; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hampton O M → Elk Stone Pit; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hampton O M → O M Hampton Stone Company; 1979-01-01 to current/open; source msha-controller-operator-history