# Relationship history for MSHA mine 0301639

Current hierarchy: **Lakin Rickey H → R H L Enterprises → Willis Crystal Mine**

- 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:** Rickard Mining → Willis Crystal Mine; 1989-08-01 to 1992-03-24; source msha-controller-operator-history
- **controller_controls_mine:** Rickard Danny → Willis Crystal Mine; 1989-08-01 to 1992-03-24; source msha-controller-operator-history
- **controller_controls_operator:** Rickard Danny → Rickard Mining; 1989-08-01 to 1992-03-24; source msha-controller-operator-history
- **operator_operates_mine:** R H L Enterprises → Willis Crystal Mine; 1992-03-25 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Lakin Rickey H → Willis Crystal Mine; 1992-03-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lakin Rickey H → R H L Enterprises; 1992-03-25 to current/open; source msha-controller-operator-history