# Relationship history for MSHA mine 1516847

Current hierarchy: **Potter Gordon → Cougar Processing Corp → Plant No 1**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Johnson Donald → Plant No 1; 1980-11-07 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Lamplighter Mining Company Inc → Plant No 1; 1990-03-01 to 1996-01-24; source msha-controller-operator-history
- **controller_controls_operator:** Johnson Donald → Lamplighter Mining Company Inc; 1990-03-01 to 1996-01-24; source msha-controller-operator-history
- **operator_operates_mine:** Cougar Processing Corp → Plant No 1; 1996-01-25 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Potter Gordon → Plant No 1; 1996-01-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Potter Gordon → Cougar Processing Corp; 1996-01-25 to current/open; source msha-controller-operator-history