# Relationship history for MSHA mine 4609037

Current hierarchy: **Mary J  Brown → Valley Mining, Inc. → Airport Strip**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Mary J  Brown → Airport Strip; 1972-12-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Valley Mining, Inc. → Airport Strip; 2004-04-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mary J  Brown → Valley Mining, Inc.; 2004-04-27 to current/open; source msha-controller-operator-history