# Relationship history for MSHA mine 4702787

Current hierarchy: **Mary A  LaCount; Michael W  Mengel → Cam Construction Company, Inc. → Cam Construction Company, Inc.**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Cam Construction Company Inc → Cam Construction Company, Inc.; 1985-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mary A  LaCount et al → Cam Construction Company, Inc.; 1985-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mary A  LaCount et al → Cam Construction Company Inc; 1985-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael W  Mengel  et al → Cam Construction Company Inc; 1985-06-01 to current/open; source msha-controller-operator-history