# Relationship history for MSHA mine 4300160

Current hierarchy: **Trampas  Demers → SHELBURNE LIMESTONE CORP → SHELBURNE QUARRY**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Shelburne Limestone Corp → SHELBURNE QUARRY; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Dennis R  Demers → SHELBURNE QUARRY; 1950-01-01 to 2017-04-30; source msha-controller-operator-history
- **controller_controls_operator:** Dennis R  Demers → Shelburne Limestone Corp; 1950-01-01 to 2017-04-30; source msha-controller-operator-history
- **controller_controls_mine:** Trampas  Demers → SHELBURNE QUARRY; 2017-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Trampas  Demers → Shelburne Limestone Corp; 2017-05-01 to current/open; source msha-controller-operator-history