# Relationship history for MSHA mine 3101896

Current hierarchy: **Butner Ed → Tri-County Stone Company → BUTNER QUARRY AND YARD**

- 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:** Tri-County Stone Company → BUTNER QUARRY AND YARD; 1979-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Butner Ed → BUTNER QUARRY AND YARD; 1979-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Butner Ed → Tri-County Stone Company; 1979-06-01 to current/open; source msha-controller-operator-history