# Relationship history for MSHA mine 3303841

Current hierarchy: **Ogle Delbert → Whitewater Sand & Gravel Company → Dry Fork Plant**

- 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

- **controller_controls_mine:** Ogle Delbert → Dry Fork Plant; 1979-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Whitewater Sand & Gravel Company → Dry Fork Plant; 1980-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ogle Delbert → Whitewater Sand & Gravel Company; 1980-09-01 to current/open; source msha-controller-operator-history