# Relationship history for MSHA mine 1800677

Current hierarchy: **Wilhelm Gilbert → Wilhelm Coal Inc → Wassel 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

- **controller_controls_mine:** Wilhelm Gilbert → Wassel Mine; 1977-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Blue Chip Mining Company Inc → Wassel Mine; 1980-07-01 to 1981-02-23; source msha-controller-operator-history
- **controller_controls_mine:** Plavi Joe → Wassel Mine; 1980-07-01 to 1981-02-23; source msha-controller-operator-history
- **controller_controls_operator:** Plavi Joe → Blue Chip Mining Company Inc; 1980-07-01 to 1981-02-23; source msha-controller-operator-history
- **operator_operates_mine:** Cabin Run Coal Company Inc → Wassel Mine; 1981-02-24 to 1982-02-17; source msha-controller-operator-history
- **controller_controls_mine:** Winebrenner Joseph W → Wassel Mine; 1981-02-24 to 1982-02-17; source msha-controller-operator-history
- **controller_controls_operator:** Winebrenner Joseph W → Cabin Run Coal Company Inc; 1981-02-24 to 1982-02-17; source msha-controller-operator-history
- **operator_operates_mine:** Best Coal Stripping Inc → Wassel Mine; 1982-02-18 to 1983-03-07; source msha-controller-operator-history
- **controller_controls_mine:** Romani Francis J → Wassel Mine; 1982-02-18 to 1983-03-07; source msha-controller-operator-history
- **controller_controls_operator:** Romani Francis J → Best Coal Stripping Inc; 1982-02-18 to 1983-03-07; source msha-controller-operator-history
- **operator_operates_mine:** Wilhelm Coal Inc → Wassel Mine; 1983-03-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Wilhelm Gilbert → Wilhelm Coal Inc; 1983-03-08 to current/open; source msha-controller-operator-history