# Relationship history for MSHA mine 3600968

Current hierarchy: **ACNR Holdings, Inc → Washington County Land Resources, Inc. → Maple Creek Preparation 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

- **operator_operates_mine:** United States Steel Mining Company Inc → Maple Creek Preparation Plant; 1950-01-01 to 1995-06-29; source msha-controller-operator-history
- **controller_controls_mine:** Usx Corp → Maple Creek Preparation Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Usx Corp → United States Steel Mining Company Inc; 1950-01-01 to 1995-06-29; source msha-controller-operator-history
- **operator_operates_mine:** Maple Creek Mining Incorporated → Maple Creek Preparation Plant; 1995-06-30 to 2020-09-16; source msha-controller-operator-history
- **controller_controls_mine:** Robert E  Murray → Maple Creek Preparation Plant; 1995-06-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert E  Murray → Maple Creek Mining Incorporated; 1995-06-30 to 2020-09-16; source msha-controller-operator-history
- **operator_operates_mine:** Washington County Land Resources, Inc. → Maple Creek Preparation Plant; 2020-09-17 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** ACNR Holdings, Inc → Maple Creek Preparation Plant; 2020-09-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** ACNR Holdings, Inc → Washington County Land Resources, Inc.; 2020-09-17 to current/open; source msha-controller-operator-history