# Relationship history for MSHA mine 1100031

Current hierarchy: **Richard  Hurst; Carolyn  Hurst → Chester Quarry Company Inc → Chester 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:** Chester Quarry Company → Chester Quarry; 1950-01-01 to 1987-01-09; source msha-controller-operator-history
- **controller_controls_mine:** Schute Lester & W W → Chester Quarry; 1950-01-01 to 1987-01-09; source msha-controller-operator-history
- **controller_controls_operator:** Schute Lester & W W → Chester Quarry Company; 1950-01-01 to 1987-01-09; source msha-controller-operator-history
- **operator_operates_mine:** Chester Quarry Company Inc → Chester Quarry; 1987-01-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Richard  Hurst  et al → Chester Quarry; 1987-01-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Richard  Hurst  et al → Chester Quarry Company Inc; 1987-01-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Carolyn  Hurst  et al → Chester Quarry Company Inc; 1987-01-10 to current/open; source msha-controller-operator-history