# Relationship history for MSHA mine 4606229

Current hierarchy: **Frisco Donald → D M & S Inc → No 1 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 & S Inc → No 1 Mine; 1980-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Frisco Donald Et Al → No 1 Mine; 1980-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Frisco Donald Et Al → D M & S Inc; 1980-10-01 to current/open; source msha-controller-operator-history