# Relationship history for MSHA mine 1518115

Current hierarchy: **CONSOL Energy Inc → Consol Of Kentucky Inc → Big Springs E1 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** CONSOL Energy Inc → Big Springs E1 Mine; 1986-07-31 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Consol Of Kentucky Inc → Big Springs E1 Mine; 1998-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CONSOL Energy Inc → Consol Of Kentucky Inc; 1998-11-01 to current/open; source msha-controller-operator-history