# Relationship history for MSHA mine 4701147

Current hierarchy: **Eldon L  Duncan → Wisconsin Frac Sand Inc → MAIDEN ROCK**

- 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:** Wisconsin Frac Sand Inc → MAIDEN ROCK; 1991-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Eldon L  Duncan → MAIDEN ROCK; 1991-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Eldon L  Duncan → Wisconsin Frac Sand Inc; 1991-04-01 to current/open; source msha-controller-operator-history