# Relationship history for MSHA mine 4102589

Current hierarchy: **Dobson Johnny → D & M Contractors → Joe Wallace 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

- **operator_operates_mine:** D & M Contractors → Joe Wallace Mine; 1976-04-26 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Dobson Johnny → Joe Wallace Mine; 1976-04-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dobson Johnny → D & M Contractors; 1976-04-26 to current/open; source msha-controller-operator-history