# Relationship history for MSHA mine 3302765

Current hierarchy: **Holmes Limestone Company → Horizon Coal Corp → Horizon Strip-Strasburg**

- 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

- **operator_operates_mine:** Blue Creek Coal Inc → Horizon Strip-Strasburg; 1950-01-01 to 1977-07-24; source msha-controller-operator-history
- **controller_controls_mine:** Fabrizo Clarence → Horizon Strip-Strasburg; 1950-01-01 to 1977-07-24; source msha-controller-operator-history
- **controller_controls_operator:** Fabrizo Clarence → Blue Creek Coal Inc; 1950-01-01 to 1977-07-24; source msha-controller-operator-history
- **controller_controls_mine:** U S Filter Corp → Horizon Strip-Strasburg; 1976-11-01 to 1981-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Horizon Coal Corp → Horizon Strip-Strasburg; 1977-07-25 to 1981-03-31; source msha-controller-operator-history
- **controller_controls_operator:** U S Filter Corp → Horizon Coal Corp; 1977-07-25 to 1981-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Horizon Coal Corp → Horizon Strip-Strasburg; 1981-04-01 to 1982-11-21; source msha-controller-operator-history
- **controller_controls_mine:** Ashland Inc et al → Horizon Strip-Strasburg; 1981-04-01 to 1982-12-16; source msha-controller-operator-history
- **controller_controls_operator:** Ashland Inc et al → Horizon Coal Corp; 1981-04-01 to 1982-11-21; source msha-controller-operator-history
- **operator_operates_mine:** Horizon Coal Corp → Horizon Strip-Strasburg; 1982-11-22 to 1985-11-18; source msha-controller-operator-history
- **controller_controls_mine:** Compass International Corp → Horizon Strip-Strasburg; 1982-11-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Compass International Corp → Horizon Coal Corp; 1982-11-22 to 1985-11-18; source msha-controller-operator-history
- **operator_operates_mine:** Horizon Coal Corp → Horizon Strip-Strasburg; 1985-11-19 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Holmes Limestone Company → Horizon Strip-Strasburg; 1985-11-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Holmes Limestone Company → Horizon Coal Corp; 1985-11-19 to current/open; source msha-controller-operator-history