# Relationship history for MSHA mine 2300046

Current hierarchy: **Keith  Wilkinson → Keystone Quarry → KEYSTONE 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:** Deitz Hill Development Company → KEYSTONE QUARRY; 1950-01-01 to 1985-02-22; source msha-controller-operator-history
- **controller_controls_mine:** W E  Thomson Jr → KEYSTONE QUARRY; 1950-01-01 to 1985-02-22; source msha-controller-operator-history
- **controller_controls_operator:** W E  Thomson Jr → Deitz Hill Development Company; 1950-01-01 to 1985-02-22; source msha-controller-operator-history
- **operator_operates_mine:** Keystone Quarry → KEYSTONE QUARRY; 1985-02-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Keith  Wilkinson → KEYSTONE QUARRY; 1985-02-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Keith  Wilkinson → Keystone Quarry; 1985-02-23 to current/open; source msha-controller-operator-history