# Relationship history for MSHA mine 4201883

Current hierarchy: **Steven C  Heaton → Western Construction Inc → Western Construction Portable Plant**

- 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

- **controller_controls_mine:** Richard J  Heaton → Western Construction Portable Plant; 1950-01-01 to 2024-09-09; source msha-controller-operator-history
- **operator_operates_mine:** Western Construction Inc → Western Construction Portable Plant; 1984-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Richard J  Heaton → Western Construction Inc; 1984-06-01 to 2024-09-09; source msha-controller-operator-history
- **controller_controls_mine:** Steven C  Heaton → Western Construction Portable Plant; 2024-09-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Steven C  Heaton → Western Construction Inc; 2024-09-10 to current/open; source msha-controller-operator-history