# Relationship history for MSHA mine 2602128

Current hierarchy: **Dastrup Marylene R → Sevier Excavating & Construction Company → Nevada Gypsum**

- 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:** Nevada Gypsum & Mining → Nevada Gypsum; 1989-11-01 to 1992-02-18; source msha-controller-operator-history
- **controller_controls_mine:** Cole Al → Nevada Gypsum; 1989-11-01 to 1992-02-18; source msha-controller-operator-history
- **controller_controls_operator:** Cole Al → Nevada Gypsum & Mining; 1989-11-01 to 1992-02-18; source msha-controller-operator-history
- **operator_operates_mine:** Sevier Excavating & Construction Company → Nevada Gypsum; 1992-02-19 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Dastrup Marylene R → Nevada Gypsum; 1992-02-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dastrup Marylene R → Sevier Excavating & Construction Company; 1992-02-19 to current/open; source msha-controller-operator-history