# Relationship history for MSHA mine 3604769

Current hierarchy: **Keslar Robert S → Keslar Coal Company Inc → Ralphton #1 Mine**

- 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:** Hiysota Fuel Company Inc → Ralphton #1 Mine; 1973-12-01 to 1981-08-31; source msha-controller-operator-history
- **controller_controls_mine:** Caola Joseph R → Ralphton #1 Mine; 1973-12-01 to 1981-08-31; source msha-controller-operator-history
- **controller_controls_operator:** Caola Joseph R → Hiysota Fuel Company Inc; 1973-12-01 to 1981-08-31; source msha-controller-operator-history
- **operator_operates_mine:** Hiysota Fuel Company Inc → Ralphton #1 Mine; 1981-09-01 to 1984-02-01; source msha-controller-operator-history
- **controller_controls_mine:** Jamison Philip R → Ralphton #1 Mine; 1981-09-01 to 1984-02-01; source msha-controller-operator-history
- **controller_controls_operator:** Jamison Philip R → Hiysota Fuel Company Inc; 1981-09-01 to 1984-02-01; source msha-controller-operator-history
- **operator_operates_mine:** Keslar Coal Company Inc → Ralphton #1 Mine; 1984-02-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Keslar Robert S → Ralphton #1 Mine; 1984-02-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Keslar Robert S → Keslar Coal Company Inc; 1984-02-02 to current/open; source msha-controller-operator-history