# Relationship history for MSHA mine 2101823

Current hierarchy: **Holm Norman D → H & S Asphalt Company → Nemeth Pit & Mill**

- 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:** H & S Asphalt Company → Nemeth Pit & Mill; 1950-01-01 to 1980-10-15; source msha-controller-operator-history
- **controller_controls_mine:** Holm Norman D → Nemeth Pit & Mill; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Holm Norman D → H & S Asphalt Company; 1950-01-01 to 1980-10-15; source msha-controller-operator-history
- **controller_controls_mine:** John H  Stommes → Nemeth Pit & Mill; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Stommes Construction Inc → Nemeth Pit & Mill; 1980-10-16 to 1980-11-13; source msha-controller-operator-history
- **controller_controls_operator:** John H  Stommes → Stommes Construction Inc; 1980-10-16 to 1980-11-13; source msha-controller-operator-history
- **operator_operates_mine:** H & S Asphalt Company → Nemeth Pit & Mill; 1980-11-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Holm Norman D → H & S Asphalt Company; 1980-11-14 to current/open; source msha-controller-operator-history