# Relationship history for MSHA mine 3302675

Current hierarchy: **Ronald E  Watson → Watson Gravel Inc → Spring Valley 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:** Moraine Materials Company → Spring Valley Pit; 1950-01-01 to 1988-12-05; source msha-controller-operator-history
- **controller_controls_mine:** George E  Kling → Spring Valley Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** George E  Kling → Moraine Materials Company; 1950-01-01 to 1988-12-05; source msha-controller-operator-history
- **controller_controls_mine:** Ronald E  Watson → Spring Valley Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Watson Gravel Inc → Spring Valley Pit; 1988-12-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ronald E  Watson → Watson Gravel Inc; 1988-12-06 to current/open; source msha-controller-operator-history