# Relationship history for MSHA mine 3303321

Current hierarchy: **Charles R  Wibright → Mechanicsburg Sand & Gravel Inc → Mechanicsburg Sand & Gravel Inc**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Mechanicsburg Sand & Gravel Inc → Mechanicsburg Sand & Gravel Inc; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** James G  Cushman → Mechanicsburg Sand & Gravel Inc; 1950-01-01 to 2025-06-29; source msha-controller-operator-history
- **controller_controls_operator:** James G  Cushman → Mechanicsburg Sand & Gravel Inc; 1950-01-01 to 2025-06-29; source msha-controller-operator-history
- **controller_controls_mine:** Charles R  Wibright → Mechanicsburg Sand & Gravel Inc; 2025-06-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Charles R  Wibright → Mechanicsburg Sand & Gravel Inc; 2025-06-30 to current/open; source msha-controller-operator-history