# Relationship history for MSHA mine 0404260

Current hierarchy: **Northup John E → John E Northup Enterprises → Bear River Plant**

- 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:** Hemphill Brothers Inc → Bear River Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Hemphill Brothers Inc → Bear River Plant; 1978-03-09 to 1988-08-31; source msha-controller-operator-history
- **controller_controls_operator:** Hemphill Brothers Inc → Hemphill Brothers Inc; 1978-03-09 to 1988-08-31; source msha-controller-operator-history
- **operator_operates_mine:** John E Northup Enterprises → Bear River Plant; 1988-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Northup John E → Bear River Plant; 1988-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Northup John E → John E Northup Enterprises; 1988-09-01 to current/open; source msha-controller-operator-history