# Relationship history for MSHA mine 0504141

Current hierarchy: **Cross Marvin D → South Platte Aggregates Inc → Brighton 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:** Southplatte Aggregates Inc → Brighton Pit; 1986-05-01 to 1987-07-01; source msha-controller-operator-history
- **controller_controls_mine:** Frick Robert L → Brighton Pit; 1986-05-01 to 1987-07-01; source msha-controller-operator-history
- **controller_controls_operator:** Frick Robert L → Southplatte Aggregates Inc; 1986-05-01 to 1987-07-01; source msha-controller-operator-history
- **operator_operates_mine:** South Platte Aggregates Inc → Brighton Pit; 1987-07-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Cross Marvin D → Brighton Pit; 1987-07-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cross Marvin D → South Platte Aggregates Inc; 1987-07-02 to current/open; source msha-controller-operator-history