# Relationship history for MSHA mine 2801023

Current hierarchy: **David M Vander Groef → Wantage Excavating Co., Inc. → Space Farms 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:** Wantage Excavating Co., Inc. → Space Farms Pit; 2009-03-24 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Evelyn  Vander Groef → Space Farms Pit; 2009-03-24 to 2021-08-30; source msha-controller-operator-history
- **controller_controls_operator:** Evelyn  Vander Groef → Wantage Excavating Co., Inc.; 2009-03-24 to 2021-08-30; source msha-controller-operator-history
- **controller_controls_mine:** David M Vander Groef → Space Farms Pit; 2021-08-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David M Vander Groef → Wantage Excavating Co., Inc.; 2021-08-31 to current/open; source msha-controller-operator-history