# Relationship history for MSHA mine 1503120

Current hierarchy: **Hamilton J Byron → Four H Coal Company Inc → No Ie-68**

- 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:** Ligon Preparation Company → No Ie-68; 1950-01-01 to 1981-09-21; source msha-controller-operator-history
- **controller_controls_mine:** Hall Hargis → No Ie-68; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hall Hargis → Ligon Preparation Company; 1950-01-01 to 1981-09-21; source msha-controller-operator-history
- **operator_operates_mine:** Four H Coal Company Inc → No Ie-68; 1981-09-22 to 1982-02-03; source msha-controller-operator-history
- **controller_controls_mine:** Hamilton J Byron → No Ie-68; 1981-09-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hamilton J Byron → Four H Coal Company Inc; 1981-09-22 to 1982-02-03; source msha-controller-operator-history
- **operator_operates_mine:** Newsome Coal Company → No Ie-68; 1982-02-04 to 1983-01-25; source msha-controller-operator-history
- **controller_controls_mine:** Newsome Donald--Allard G & Darling → No Ie-68; 1982-02-04 to 1983-01-25; source msha-controller-operator-history
- **controller_controls_operator:** Newsome Donald--Allard G & Darling → Newsome Coal Company; 1982-02-04 to 1983-01-25; source msha-controller-operator-history
- **operator_operates_mine:** Four H Coal Company Inc → No Ie-68; 1983-01-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hamilton J Byron → Four H Coal Company Inc; 1983-01-26 to current/open; source msha-controller-operator-history