# Relationship history for MSHA mine 3800639

Current hierarchy: **Dewitt Byron R → Beech Island Sand & Gravel → Bell 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Bonsal W R Iii → Bell Mine; 1950-01-01 to 2001-10-24; source msha-controller-operator-history
- **operator_operates_mine:** W R Bonsal Company → Bell Mine; 1989-05-01 to 1992-05-03; source msha-controller-operator-history
- **controller_controls_operator:** Bonsal W R Iii → W R Bonsal Company; 1989-05-01 to 1992-05-03; source msha-controller-operator-history
- **operator_operates_mine:** Beech Island Sand & Gravel → Bell Mine; 1992-05-04 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Dewitt Byron R → Bell Mine; 1992-05-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dewitt Byron R → Beech Island Sand & Gravel; 1992-05-04 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → Bell Mine; 2001-10-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → W R Bonsal Company; 2001-10-25 to 1992-05-03; source msha-controller-operator-history