# Relationship history for MSHA mine 4405287

Current hierarchy: **Hobbs Danny R → Hobbs Brothers Coal Company Inc → No 18**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Hobbs Danny R → No 18; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Hobbs Brothers Coal Company Inc → No 18; 1979-09-01 to 1991-05-22; source msha-controller-operator-history
- **controller_controls_operator:** Hobbs Danny R → Hobbs Brothers Coal Company Inc; 1979-09-01 to 1991-05-22; source msha-controller-operator-history
- **operator_operates_mine:** K & T Coal Company Inc → No 18; 1991-05-23 to 1992-04-06; source msha-controller-operator-history
- **controller_controls_mine:** Shortridge Keaster Et Al → No 18; 1991-05-23 to 1992-04-06; source msha-controller-operator-history
- **controller_controls_operator:** Shortridge Keaster Et Al → K & T Coal Company Inc; 1991-05-23 to 1992-04-06; source msha-controller-operator-history
- **operator_operates_mine:** Hobbs Brothers Coal Company Inc → No 18; 1992-04-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hobbs Danny R → Hobbs Brothers Coal Company Inc; 1992-04-07 to current/open; source msha-controller-operator-history