# Relationship history for MSHA mine 3304211

Current hierarchy: **Johnson Robert A Jr → S-B Coal Inc → Deville Strip**

- 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

- **operator_operates_mine:** S-B Coal Inc → Deville Strip; 1990-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Johnson Robert A Jr Et Al → Deville Strip; 1990-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Johnson Robert A Jr Et Al → S-B Coal Inc; 1990-07-01 to current/open; source msha-controller-operator-history