# Relationship history for MSHA mine 2600205

Current hierarchy: **Bullion Monarch & American Mining → Monarch Milling → Austin Mill**

- 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:** Austin Milling Company → Austin Mill; 1950-01-01 to 1980-02-28; source msha-controller-operator-history
- **controller_controls_mine:** Austin Milling Company → Austin Mill; 1950-01-01 to 1980-02-28; source msha-controller-operator-history
- **controller_controls_operator:** Austin Milling Company → Austin Milling Company; 1950-01-01 to 1980-02-28; source msha-controller-operator-history
- **operator_operates_mine:** Monarch Milling → Austin Mill; 1980-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bullion Monarch & American Mining → Austin Mill; 1980-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bullion Monarch & American Mining → Monarch Milling; 1980-03-01 to current/open; source msha-controller-operator-history