# Relationship history for MSHA mine 3301354

Current hierarchy: **Pioneer Natural Resources USA Incorporated → Premier Silica LLC → Glass Rock Operation**

- 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:** Premier Silica LLC → Glass Rock Operation; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Oglebay Norton Company → Glass Rock Operation; 1950-01-01 to 2008-02-12; source msha-controller-operator-history
- **controller_controls_operator:** Oglebay Norton Company → Premier Silica LLC; 1950-01-01 to 2008-02-12; source msha-controller-operator-history
- **controller_controls_mine:** Carmeuse Holding SA → Glass Rock Operation; 2008-02-13 to 2012-04-01; source msha-controller-operator-history
- **controller_controls_operator:** Carmeuse Holding SA → Premier Silica LLC; 2008-02-13 to 2012-04-01; source msha-controller-operator-history
- **controller_controls_mine:** Pioneer Natural Resources USA Incorporated → Glass Rock Operation; 2012-04-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Pioneer Natural Resources USA Incorporated → Premier Silica LLC; 2012-04-02 to current/open; source msha-controller-operator-history