# Relationship history for MSHA mine 1513109

Current hierarchy: **Benzick Larry → Unicorn Coal Resources Inc → Unicorn No 1**

- 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:** Associated Producers & Miners Inc → Unicorn No 1; 1981-09-01 to 1982-07-11; source msha-controller-operator-history
- **controller_controls_mine:** Crosby Wendell A → Unicorn No 1; 1981-09-01 to 1982-08-01; source msha-controller-operator-history
- **controller_controls_operator:** Crosby Wendell A → Associated Producers & Miners Inc; 1981-09-01 to 1982-07-11; source msha-controller-operator-history
- **operator_operates_mine:** Unicorn Coal Resources Inc → Unicorn No 1; 1982-07-12 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Benzick Larry → Unicorn No 1; 1982-07-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Benzick Larry → Unicorn Coal Resources Inc; 1982-07-12 to current/open; source msha-controller-operator-history