# Relationship history for MSHA mine 4104086

Current hierarchy: **Falls County-Tx → Falls County Road & Bridge Department → HAY GRAVEL PIT**

- 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

- **operator_operates_mine:** Falls County Road & Bridge Department → HAY GRAVEL PIT; 1999-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Falls County-Tx → HAY GRAVEL PIT; 1999-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Falls County-Tx → Falls County Road & Bridge Department; 1999-06-01 to current/open; source msha-controller-operator-history