# Relationship history for MSHA mine 2102570

Current hierarchy: **WSG Acquisition Corp → Wissota Sand & Gravel Company → Curtis Pit And Mill**

- 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:** Wissota Sand & Gravel Company → Curtis Pit And Mill; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Wissota Sand & Gravel Company → Curtis Pit And Mill; 1950-01-01 to 2019-10-30; source msha-controller-operator-history
- **controller_controls_operator:** Wissota Sand & Gravel Company → Wissota Sand & Gravel Company; 1950-01-01 to 2019-10-30; source msha-controller-operator-history
- **controller_controls_mine:** WSG Acquisition Corp → Curtis Pit And Mill; 2019-10-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** WSG Acquisition Corp → Wissota Sand & Gravel Company; 2019-10-31 to current/open; source msha-controller-operator-history