# Relationship history for MSHA mine 3605901

Current hierarchy: **Thompson Dallas & Leroy → Thompson & Phillips Clay Company → Sanborn No 1 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Thompson & Phillips Clay Company → Sanborn No 1 Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Thompson Dallas & Leroy Et Al → Sanborn No 1 Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thompson Dallas & Leroy Et Al → Thompson & Phillips Clay Company; 1950-01-01 to current/open; source msha-controller-operator-history