# Relationship history for MSHA mine 4606236

Current hierarchy: **Hylton Tracy W → Perry & Hylton Inc → Countyline Strip**

- 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 → Countyline Strip; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Graybeal Carl N Et Al → Countyline Strip; 1978-10-30 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Graybeals Indian Creek Coal Company Inc → Countyline Strip; 1980-09-01 to 1983-08-09; source msha-controller-operator-history
- **controller_controls_operator:** Graybeal Carl N Et Al → Graybeals Indian Creek Coal Company Inc; 1980-09-01 to 1983-08-09; source msha-controller-operator-history
- **operator_operates_mine:** Perry & Hylton Inc → Countyline Strip; 1983-08-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hylton Tracy W → Perry & Hylton Inc; 1983-08-10 to current/open; source msha-controller-operator-history