# Relationship history for MSHA mine 4002624

Current hierarchy: **Brewer J B & Jimmy Jones → B & J Excavating Inc → 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Brewer J B & Jimmy Jones → No 1 Surface; 1978-03-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** B & J Excavating Inc → No 1 Surface; 1980-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Brewer J B & Jimmy Jones → B & J Excavating Inc; 1980-07-01 to current/open; source msha-controller-operator-history