# Relationship history for MSHA mine 4002778

Current hierarchy: **Gibson Lee → Rich Mountain Coal Company → No 1 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:** Rich Mountain Coal Company → No 1 Mine; 1982-03-01 to 1983-02-02; source msha-controller-operator-history
- **controller_controls_mine:** Gibson Lee → No 1 Mine; 1982-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gibson Lee → Rich Mountain Coal Company; 1982-03-01 to 1983-02-02; source msha-controller-operator-history
- **operator_operates_mine:** E & R Coal Company → No 1 Mine; 1983-02-03 to 1987-11-04; source msha-controller-operator-history
- **controller_controls_mine:** Ridenour Marvin → No 1 Mine; 1983-02-03 to 1987-11-04; source msha-controller-operator-history
- **controller_controls_operator:** Ridenour Marvin → E & R Coal Company; 1983-02-03 to 1987-11-04; source msha-controller-operator-history
- **operator_operates_mine:** Rich Mountain Coal Company → No 1 Mine; 1987-11-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gibson Lee → Rich Mountain Coal Company; 1987-11-05 to current/open; source msha-controller-operator-history