# Relationship history for MSHA mine 3503942

Current hierarchy: **Chad L  Williams → Chad Williams → Return Association**

- 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:** Chad Williams → Return Association; 2023-03-21 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Chad L  Williams → Return Association; 2023-04-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Chad L  Williams → Chad Williams; 2023-04-05 to current/open; source msha-controller-operator-history