# Relationship history for MSHA mine 4404550

Current hierarchy: **Webb Bernard → Big Branch 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:** Bryant Coal Company → No 1 Mine; 1976-11-01 to 1977-02-27; source msha-controller-operator-history
- **controller_controls_mine:** Bryant Creed Jr-Creed Sr-Roy David Jr & Joe → No 1 Mine; 1976-11-01 to 1977-02-27; source msha-controller-operator-history
- **controller_controls_operator:** Bryant Creed Jr-Creed Sr-Roy David Jr & Joe → Bryant Coal Company; 1976-11-01 to 1977-02-27; source msha-controller-operator-history
- **operator_operates_mine:** Big Branch Coal Company → No 1 Mine; 1977-02-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Webb Bernard → No 1 Mine; 1977-02-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Webb Bernard → Big Branch Coal Company; 1977-02-28 to current/open; source msha-controller-operator-history