# Relationship history for MSHA mine 0201903

Current hierarchy: **Crain Quincy R → Quincy R Crain → Ida**

- 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:** Petro-Chem Inc → Ida; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Petro-Chem Inc → Ida; 1979-01-01 to 1980-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Petro-Chem Inc → Petro-Chem Inc; 1979-01-01 to 1980-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Quincy R Crain → Ida; 1980-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Crain Quincy R → Ida; 1980-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Crain Quincy R → Quincy R Crain; 1980-04-01 to current/open; source msha-controller-operator-history