# Relationship history for MSHA mine 4502951

Current hierarchy: **Eldridge Ernest & Richard Marshall → Eldridge-Marshal Associated Contr → Crown-Cathlamet Quarry**

- 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:** Eldridge-Marshal Associated Contr → Crown-Cathlamet Quarry; 1981-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Eldridge Ernest & Richard Marshall → Crown-Cathlamet Quarry; 1981-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Eldridge Ernest & Richard Marshall → Eldridge-Marshal Associated Contr; 1981-10-01 to current/open; source msha-controller-operator-history