# Relationship history for MSHA mine 1510491

Current hierarchy: **Horizon Natural Resources Incorporated → Straight Creek Coal Resources Company → Washer Plant**

- 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:** Harbert Construction Corp → Washer Plant; 1976-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Brownies Creek Collieries Inc → Washer Plant; 1977-06-01 to 1981-09-14; source msha-controller-operator-history
- **controller_controls_operator:** Harbert Construction Corp → Brownies Creek Collieries Inc; 1977-06-01 to 1981-09-14; source msha-controller-operator-history
- **controller_controls_mine:** Cyprus Amax Minerals Company → Washer Plant; 1981-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Cyprus Cumberland Coal Corp → Washer Plant; 1981-09-15 to 1998-06-28; source msha-controller-operator-history
- **controller_controls_operator:** Cyprus Amax Minerals Company → Cyprus Cumberland Coal Corp; 1981-09-15 to 1998-06-28; source msha-controller-operator-history
- **operator_operates_mine:** Straight Creek Coal Resources Company → Washer Plant; 1998-06-29 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Horizon Natural Resources Incorporated → Washer Plant; 1998-06-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Horizon Natural Resources Incorporated → Straight Creek Coal Resources Company; 1998-06-29 to current/open; source msha-controller-operator-history