# Relationship history for MSHA mine 3600269

Current hierarchy: **Gary A  Mahan → Pen Roc Inc → Pen Roc West**

- 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:** White Pigment Corp → Pen Roc West; 1950-01-01 to 1980-09-21; source msha-controller-operator-history
- **controller_controls_mine:** Cyprus Mines Corp → Pen Roc West; 1950-01-01 to 1980-09-21; source msha-controller-operator-history
- **controller_controls_operator:** Cyprus Mines Corp → White Pigment Corp; 1950-01-01 to 1980-09-21; source msha-controller-operator-history
- **operator_operates_mine:** White Pigment Corp → Pen Roc West; 1980-09-22 to 1987-09-03; source msha-controller-operator-history
- **controller_controls_mine:** Cyprus Minerals Corp & Pluess-Staufer Industries → Pen Roc West; 1980-09-22 to 1987-09-03; source msha-controller-operator-history
- **controller_controls_operator:** Cyprus Minerals Corp & Pluess-Staufer Industries → White Pigment Corp; 1980-09-22 to 1987-09-03; source msha-controller-operator-history
- **operator_operates_mine:** White Pigment Corp → Pen Roc West; 1987-09-04 to 1990-07-30; source msha-controller-operator-history
- **controller_controls_mine:** Omya Industries Inc → Pen Roc West; 1987-09-04 to 1990-07-30; source msha-controller-operator-history
- **controller_controls_operator:** Omya Industries Inc → White Pigment Corp; 1987-09-04 to 1990-07-30; source msha-controller-operator-history
- **controller_controls_mine:** Gary A  Mahan  et al → Pen Roc West; 1989-12-07 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Pen Roc Inc → Pen Roc West; 1990-07-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gary A  Mahan  et al → Pen Roc Inc; 1990-07-31 to current/open; source msha-controller-operator-history