# Relationship history for MSHA mine 1502000

Current hierarchy: **Bow Valley Industries Ltd → Bow Valley Coal Resources Inc → Rocco 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:** Rocco Coals Inc → Rocco Mine; 1950-01-01 to 1976-02-04; source msha-controller-operator-history
- **controller_controls_mine:** Snapp Hugh C → Rocco Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Snapp Hugh C → Rocco Coals Inc; 1950-01-01 to 1976-02-04; source msha-controller-operator-history
- **controller_controls_mine:** Flying Diamond Oil Corp → Rocco Mine; 1950-01-01 to 1978-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Bow Valley Industries Ltd → Rocco Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Coal Resources Corp → Rocco Mine; 1976-02-05 to 1978-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Flying Diamond Oil Corp → Coal Resources Corp; 1976-02-05 to 1978-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Bow Valley Coal Resources Inc → Rocco Mine; 1978-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bow Valley Industries Ltd → Bow Valley Coal Resources Inc; 1978-06-01 to current/open; source msha-controller-operator-history