# Relationship history for MSHA mine 4606609

Current hierarchy: **Edward A  Asbury → Skyway Strip, Inc → Skyway II 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:** Hylton Tracy W → Skyway II Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Perry & Hylton Inc → Skyway II Mine; 1982-11-01 to 2010-12-09; source msha-controller-operator-history
- **controller_controls_operator:** Hylton Tracy W → Perry & Hylton Inc; 1982-11-01 to 2010-12-09; source msha-controller-operator-history
- **operator_operates_mine:** Skyway Strip, Inc → Skyway II Mine; 2010-12-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Edward A  Asbury → Skyway II Mine; 2010-12-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Edward A  Asbury → Skyway Strip, Inc; 2010-12-10 to current/open; source msha-controller-operator-history