# Relationship history for MSHA mine 2301698

Current hierarchy: **Leenerts Roger → Mexico Coal Company Inc → Sonora 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:** Mexico Coal Company Inc → Sonora Mine; 1978-05-01 to 1979-10-11; source msha-controller-operator-history
- **controller_controls_mine:** Donaldson Elmer L → Sonora Mine; 1978-05-01 to 1979-10-11; source msha-controller-operator-history
- **controller_controls_operator:** Donaldson Elmer L → Mexico Coal Company Inc; 1978-05-01 to 1979-10-11; source msha-controller-operator-history
- **operator_operates_mine:** Mexico Coal Company Inc → Sonora Mine; 1979-10-12 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Leenerts Roger → Sonora Mine; 1979-10-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Leenerts Roger → Mexico Coal Company Inc; 1979-10-12 to current/open; source msha-controller-operator-history