# Relationship history for MSHA mine 0501988

Current hierarchy: **Hank Williams Inc → Hank Williams Inc. → WILLIAMS GRAVEL PIT**

- 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:** Williams Inc → WILLIAMS GRAVEL PIT; 1950-01-01 to 1979-04-18; source msha-controller-operator-history
- **controller_controls_mine:** Williams W R → WILLIAMS GRAVEL PIT; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Williams W R → Williams Inc; 1950-01-01 to 1979-04-18; source msha-controller-operator-history
- **operator_operates_mine:** Southwestern Redimix → WILLIAMS GRAVEL PIT; 1979-04-19 to 2006-07-09; source msha-controller-operator-history
- **controller_controls_mine:** Fred  McKinney → WILLIAMS GRAVEL PIT; 1979-04-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Fred  McKinney → Southwestern Redimix; 1979-04-19 to 2006-07-09; source msha-controller-operator-history
- **operator_operates_mine:** Hank Williams Inc. → WILLIAMS GRAVEL PIT; 2006-07-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hank Williams Inc → WILLIAMS GRAVEL PIT; 2006-07-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hank Williams Inc → Hank Williams Inc.; 2006-07-10 to current/open; source msha-controller-operator-history