# Relationship history for MSHA mine 3500428

Current hierarchy: **Rod  Anderson → Barnhart Rock Products → Barnhart Quarry**

- 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:** Morrison-Knudsen Company Inc → Barnhart Quarry; 1950-01-01 to 1987-11-30; source msha-controller-operator-history
- **controller_controls_mine:** Morrison Knudsen Corp (Old) → Barnhart Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Morrison Knudsen Corp (Old) → Morrison-Knudsen Company Inc; 1950-01-01 to 1987-11-30; source msha-controller-operator-history
- **controller_controls_mine:** Burlington Resources Inc → Barnhart Quarry; 1981-11-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Meridian Aggregates Company → Barnhart Quarry; 1987-12-01 to 1991-02-28; source msha-controller-operator-history
- **controller_controls_operator:** Burlington Resources Inc → Meridian Aggregates Company; 1987-12-01 to 1991-02-28; source msha-controller-operator-history
- **operator_operates_mine:** Meridian Aggregates Company → Barnhart Quarry; 1991-03-01 to 1991-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Meridian Aggregates Company LP → Barnhart Quarry; 1991-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Meridian Aggregates Company LP → Meridian Aggregates Company; 1991-03-01 to 1991-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Barnhart Rock Products → Barnhart Quarry; 1992-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Rod  Anderson → Barnhart Quarry; 1992-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Rod  Anderson → Barnhart Rock Products; 1992-01-01 to current/open; source msha-controller-operator-history