# Relationship history for MSHA mine 1514352

Current hierarchy: **Horizon Natural Resources Incorporated → Straight Creek Coal Resources → Nix Branch Ug 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Diamond Shamrock Corp → Nix Branch Ug Mine; 1979-01-18 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Falcon Coal Company Inc → Nix Branch Ug Mine; 1983-11-01 to 1987-05-17; source msha-controller-operator-history
- **controller_controls_operator:** Diamond Shamrock Corp → Falcon Coal Company Inc; 1983-11-01 to 1987-05-17; source msha-controller-operator-history
- **operator_operates_mine:** Arch On The North Fork Inc → Nix Branch Ug Mine; 1987-05-18 to 2002-08-14; source msha-controller-operator-history
- **controller_controls_mine:** Ashland Inc et al → Nix Branch Ug Mine; 1987-05-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ashland Inc et al → Arch On The North Fork Inc; 1987-05-18 to 2002-08-14; source msha-controller-operator-history
- **controller_controls_mine:** Horizon Natural Resources Incorporated → Nix Branch Ug Mine; 1998-06-29 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Straight Creek Coal Resources → Nix Branch Ug Mine; 2002-08-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Horizon Natural Resources Incorporated → Straight Creek Coal Resources; 2002-08-15 to current/open; source msha-controller-operator-history