# Relationship history for MSHA mine 2600679

Current hierarchy: **USS Holdings Inc → U.S. Silica Company, LLC → Hazen Pit**

- 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:** Eagle Picher Filtration & Minerals Inc → Hazen Pit; 1950-01-01 to 2006-07-31; source msha-controller-operator-history
- **controller_controls_mine:** Eagle-Picher Industries Inc → Hazen Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Eagle-Picher Industries Inc → Eagle Picher Filtration & Minerals Inc; 1950-01-01 to 2006-07-31; source msha-controller-operator-history
- **controller_controls_mine:** USS Holdings Inc → Hazen Pit; 1996-03-09 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** EP Minerals LLC → Hazen Pit; 2006-08-01 to 2019-05-13; source msha-controller-operator-history
- **controller_controls_mine:** Eagle-Picher Industries Inc → Hazen Pit; 2006-08-01 to 2010-02-14; source msha-controller-operator-history
- **controller_controls_operator:** Eagle-Picher Industries Inc → EP Minerals LLC; 2006-08-01 to 2010-02-14; source msha-controller-operator-history
- **controller_controls_mine:** EP Management Corporation → Hazen Pit; 2010-02-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** EP Management Corporation → EP Minerals LLC; 2010-02-15 to 2019-05-13; source msha-controller-operator-history
- **operator_operates_mine:** U.S. Silica Company, LLC → Hazen Pit; 2019-05-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** USS Holdings Inc → U.S. Silica Company, LLC; 2019-05-14 to current/open; source msha-controller-operator-history