# Relationship history for MSHA mine 1701042

Current hierarchy: **Thomas C Sturgeon → Crooker Construction, LLC → Portable 2**

- 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

- **controller_controls_mine:** Franklin T  Crooker → Portable 2; 1950-01-01 to 2014-12-08; source msha-controller-operator-history
- **controller_controls_mine:** Thomas C Sturgeon → Portable 2; 2014-12-09 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Crooker Construction, LLC → Portable 2; 2021-01-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thomas C Sturgeon → Crooker Construction, LLC; 2021-01-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Franklin T  Crooker → Crooker Construction, LLC; 2021-01-22 to 2014-12-08; source msha-controller-operator-history