# Relationship history for MSHA mine 3600893

Current hierarchy: **Harry J  Hanchar → River Hill Coal Company Inc → Garden #1 Strip**

- 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:** Tosco Corp → Garden #1 Strip; 1950-01-01 to 1988-02-08; source msha-controller-operator-history
- **operator_operates_mine:** Garden Coal Company Inc → Garden #1 Strip; 1950-01-01 to 1976-01-01; source msha-controller-operator-history
- **controller_controls_mine:** Larson Raymond → Garden #1 Strip; 1950-01-01 to 1976-01-01; source msha-controller-operator-history
- **controller_controls_operator:** Larson Raymond → Garden Coal Company Inc; 1950-01-01 to 1976-01-01; source msha-controller-operator-history
- **operator_operates_mine:** River Hill Coal Company Inc → Garden #1 Strip; 1976-01-02 to 1988-02-08; source msha-controller-operator-history
- **controller_controls_operator:** Tosco Corp → River Hill Coal Company Inc; 1976-01-02 to 1988-02-08; source msha-controller-operator-history
- **operator_operates_mine:** River Hill Coal Company Inc → Garden #1 Strip; 1988-02-09 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Harry J  Hanchar → Garden #1 Strip; 1988-02-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Harry J  Hanchar → River Hill Coal Company Inc; 1988-02-09 to current/open; source msha-controller-operator-history