# Relationship history for MSHA mine 1512643

Current hierarchy: **Michael  Puskarich → Bluegrass Mining → Bluegrass 10-14 Surface**

- 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:** Michael  Puskarich  et al → Bluegrass 10-14 Surface; 1977-09-16 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Bluegrass Mining → Bluegrass 10-14 Surface; 1980-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael  Puskarich  et al → Bluegrass Mining; 1980-11-01 to current/open; source msha-controller-operator-history