# Relationship history for MSHA mine 2101397

Current hierarchy: **Schulze Leland F → Hector Construction Company Inc → Hector Filimore County Quarries**

- 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:** Nielsen Clarence C → Hector Filimore County Quarries; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Roverud Construction Inc → Hector Filimore County Quarries; 1950-01-01 to 1981-09-07; source msha-controller-operator-history
- **controller_controls_mine:** Curtis G Roverud et al → Hector Filimore County Quarries; 1950-01-01 to 2004-02-04; source msha-controller-operator-history
- **controller_controls_operator:** Curtis G Roverud et al → Roverud Construction Inc; 1950-01-01 to 1981-09-07; source msha-controller-operator-history
- **controller_controls_operator:** Jeff C Roverud et al → Roverud Construction Inc; 1950-01-01 to 1981-09-07; source msha-controller-operator-history
- **operator_operates_mine:** Hector Construction Company Inc → Hector Filimore County Quarries; 1981-09-08 to 1984-12-03; source msha-controller-operator-history
- **controller_controls_operator:** Nielsen Clarence C → Hector Construction Company Inc; 1981-09-08 to 1984-12-03; source msha-controller-operator-history
- **operator_operates_mine:** Hector Construction Company Inc → Hector Filimore County Quarries; 1984-12-04 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Schulze Leland F → Hector Filimore County Quarries; 1984-12-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Schulze Leland F → Hector Construction Company Inc; 1984-12-04 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** MDU Resources Group Inc → Hector Filimore County Quarries; 2004-02-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** MDU Resources Group Inc → Roverud Construction Inc; 2004-02-05 to 1981-09-07; source msha-controller-operator-history