# Relationship history for MSHA mine 1506396

Current hierarchy: **Richard L  Cooper → T & K Mining Company Inc → Welco Tipple**

- 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

- **controller_controls_mine:** Ratcliff Willard → Welco Tipple; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** T & K Mining Company → Welco Tipple; 1973-01-01 to 1976-02-02; source msha-controller-operator-history
- **controller_controls_mine:** T & K Mining Company → Welco Tipple; 1973-01-01 to 1976-02-02; source msha-controller-operator-history
- **controller_controls_operator:** T & K Mining Company → T & K Mining Company; 1973-01-01 to 1976-02-02; source msha-controller-operator-history
- **operator_operates_mine:** Upper Beaver Coal Company Inc → Welco Tipple; 1976-02-03 to 1978-04-27; source msha-controller-operator-history
- **controller_controls_operator:** Ratcliff Willard → Upper Beaver Coal Company Inc; 1976-02-03 to 1978-04-27; source msha-controller-operator-history
- **controller_controls_mine:** Richard L  Cooper → Welco Tipple; 1978-04-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** T & K Mining Company Inc → Welco Tipple; 1978-04-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Richard L  Cooper → T & K Mining Company Inc; 1978-04-28 to current/open; source msha-controller-operator-history