# Relationship history for MSHA mine 4607019

Current hierarchy: **Tracy W  Hylton II → Upper Laurel Company → No 3 Surface (3)**

- 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:** Adkins Buhl → No 3 Surface (3); 1975-11-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** B A Coal Company → No 3 Surface (3); 1985-10-01 to 1993-05-20; source msha-controller-operator-history
- **controller_controls_operator:** Adkins Buhl → B A Coal Company; 1985-10-01 to 1993-05-20; source msha-controller-operator-history
- **controller_controls_mine:** Tracy W  Hylton II → No 3 Surface (3); 1988-11-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Upper Laurel Company → No 3 Surface (3); 1993-05-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tracy W  Hylton II → Upper Laurel Company; 1993-05-21 to current/open; source msha-controller-operator-history