# Relationship history for MSHA mine 1510721

Current hierarchy: **Duke Joe → Owls Nest Coal Company Inc → No 1 Surface**

- 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:** Owls Nest Coal Company Inc → No 1 Surface; 1977-09-01 to 1979-01-09; source msha-controller-operator-history
- **controller_controls_mine:** Hamilton Mervin → No 1 Surface; 1977-09-01 to 1979-01-09; source msha-controller-operator-history
- **controller_controls_operator:** Hamilton Mervin → Owls Nest Coal Company Inc; 1977-09-01 to 1979-01-09; source msha-controller-operator-history
- **operator_operates_mine:** Owls Nest Coal Company Inc → No 1 Surface; 1979-01-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Duke Joe → No 1 Surface; 1979-01-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Duke Joe → Owls Nest Coal Company Inc; 1979-01-10 to current/open; source msha-controller-operator-history