# Relationship history for MSHA mine 3302694

Current hierarchy: **Blazer J J Construction Company → Key Coal Company Inc → Starr**

- 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:** Blazer J J Construction Company → Starr; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Key Coal Company Inc → Starr; 1973-03-01 to 1977-06-13; source msha-controller-operator-history
- **controller_controls_operator:** Blazer J J Construction Company → Key Coal Company Inc; 1973-03-01 to 1977-06-13; source msha-controller-operator-history
- **operator_operates_mine:** South Kentucky Mining Company Inc → Starr; 1977-06-14 to 1979-07-29; source msha-controller-operator-history
- **controller_controls_mine:** Bathalter Joe S → Starr; 1977-06-14 to 1979-07-29; source msha-controller-operator-history
- **controller_controls_operator:** Bathalter Joe S → South Kentucky Mining Company Inc; 1977-06-14 to 1979-07-29; source msha-controller-operator-history
- **operator_operates_mine:** Key Coal Company Inc → Starr; 1979-07-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Blazer J J Construction Company → Key Coal Company Inc; 1979-07-30 to current/open; source msha-controller-operator-history