# Relationship history for MSHA mine 0502775

Current hierarchy: **Alvidrez Mary → Cedar Canon Coal Company → Cedar Canon Strip & Auger**

- 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:** Cedar Canon Coal Company → Cedar Canon Strip & Auger; 1975-10-01 to 1977-01-03; source msha-controller-operator-history
- **controller_controls_mine:** Alvidrez Casey & Richard → Cedar Canon Strip & Auger; 1975-10-01 to 1977-01-03; source msha-controller-operator-history
- **controller_controls_operator:** Alvidrez Casey & Richard → Cedar Canon Coal Company; 1975-10-01 to 1977-01-03; source msha-controller-operator-history
- **operator_operates_mine:** Cedar Canon Coal Company → Cedar Canon Strip & Auger; 1977-01-04 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Alvidrez Mary → Cedar Canon Strip & Auger; 1977-01-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Alvidrez Mary → Cedar Canon Coal Company; 1977-01-04 to current/open; source msha-controller-operator-history