# Relationship history for MSHA mine 2001192

Current hierarchy: **Daniel R  Balkema; Ralph T  Balkema → Aggregate Resources, Inc. → Ravine Rd Pit**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Cole Brothers Contractors Inc → Ravine Rd Pit; 1950-01-01 to 1981-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Olan  Cole → Ravine Rd Pit; 1950-01-01 to 1981-04-06; source msha-controller-operator-history
- **controller_controls_operator:** Olan  Cole → Cole Brothers Contractors Inc; 1950-01-01 to 1981-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Cole Brothers Contractors Inc → Ravine Rd Pit; 1981-04-01 to 2002-01-01; source msha-controller-operator-history
- **controller_controls_mine:** Gary  Moline  et al → Ravine Rd Pit; 1981-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gary  Moline  et al → Cole Brothers Contractors Inc; 1981-04-01 to 2002-01-01; source msha-controller-operator-history
- **operator_operates_mine:** Aggregate Resources, Inc. → Ravine Rd Pit; 2002-01-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ralph T  Balkema et al → Ravine Rd Pit; 2002-01-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ralph T  Balkema et al → Aggregate Resources, Inc.; 2002-01-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Daniel R  Balkema et al → Aggregate Resources, Inc.; 2002-01-02 to current/open; source msha-controller-operator-history