# Relationship history for MSHA mine 0503225

Current hierarchy: **Cleghorn Douglas → Cleghorn Mining Company → Equinox**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Cleghorn Douglas & Lark L Washburn → Equinox; 1950-01-01 to 1981-10-19; source msha-controller-operator-history
- **operator_operates_mine:** Cleghorn & Washburn Mining Company → Equinox; 1978-03-09 to 1980-04-29; source msha-controller-operator-history
- **controller_controls_operator:** Cleghorn Douglas & Lark L Washburn → Cleghorn & Washburn Mining Company; 1978-03-09 to 1980-04-29; source msha-controller-operator-history
- **operator_operates_mine:** Cleghorn Mining Company → Equinox; 1980-04-30 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Cleghorn Douglas → Equinox; 1980-04-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cleghorn Douglas → Cleghorn Mining Company; 1980-04-30 to current/open; source msha-controller-operator-history