# Relationship history for MSHA mine 1511333

Current hierarchy: **Bruce J  Schnabel; James D  Klingbell → Independence Coal Company → No 1 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Independence Coal Company → No 1 Surface; 1978-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bruce J  Schnabel et al → No 1 Surface; 1978-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bruce J  Schnabel et al → Independence Coal Company; 1978-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James D  Klingbell et al → Independence Coal Company; 1978-05-01 to current/open; source msha-controller-operator-history