# Relationship history for MSHA mine 2103042

Current hierarchy: **Milt  Schuur → Schuur Concrete → Portable Plant #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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Milt  Schuur et al → Portable Plant #2; 1991-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Schuur Concrete → Portable Plant #2; 1991-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Milt  Schuur et al → Schuur Concrete; 1991-10-01 to current/open; source msha-controller-operator-history