# Relationship history for MSHA mine 1507060

Current hierarchy: **Day Kerney Jr → Day Coal Co Inc → No 1 Surface 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

- **controller_controls_mine:** Day Kerney Jr → No 1 Surface Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Day Coal Co Inc → No 1 Surface Mine; 1974-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Day Kerney Jr → Day Coal Co Inc; 1974-01-01 to current/open; source msha-controller-operator-history