# Relationship history for MSHA mine 2700291

Current hierarchy: **Cary G  Whipple → United Construction Corp → Portable Plant (903)**

- 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:** United Construction Corp → Portable Plant (903); 1990-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Cary G  Whipple → Portable Plant (903); 1990-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cary G  Whipple → United Construction Corp; 1990-10-01 to current/open; source msha-controller-operator-history