# Relationship history for MSHA mine 1201801

Current hierarchy: **Gremore Ken → Midnight Sun Coal Company Inc → Midnight Sun Thomas Siding**

- 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:** Midnight Sun Coal Company Inc → Midnight Sun Thomas Siding; 1980-08-01 to 1982-06-02; source msha-controller-operator-history
- **controller_controls_mine:** Meek Perry R → Midnight Sun Thomas Siding; 1980-08-01 to 1982-08-09; source msha-controller-operator-history
- **controller_controls_operator:** Meek Perry R → Midnight Sun Coal Company Inc; 1980-08-01 to 1982-06-02; source msha-controller-operator-history
- **operator_operates_mine:** Midnight Sun Coal Company Inc → Midnight Sun Thomas Siding; 1982-06-03 to 1983-06-06; source msha-controller-operator-history
- **controller_controls_mine:** Spalding George & George Petro → Midnight Sun Thomas Siding; 1982-06-03 to 1983-06-06; source msha-controller-operator-history
- **controller_controls_operator:** Spalding George & George Petro → Midnight Sun Coal Company Inc; 1982-06-03 to 1983-06-06; source msha-controller-operator-history
- **controller_controls_mine:** Gremore Ken → Midnight Sun Thomas Siding; 1983-02-25 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Midnight Sun Coal Company Inc → Midnight Sun Thomas Siding; 1983-06-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gremore Ken → Midnight Sun Coal Company Inc; 1983-06-07 to current/open; source msha-controller-operator-history