# Relationship history for MSHA mine 4703972

Current hierarchy: **Brian  Baumhardt; Tim  Baumhardt → J&J Baumhardt Aggregates → SCREENING PLANT-RENTAL**

- 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

- **controller_controls_mine:** John  Baumhardt → SCREENING PLANT-RENTAL; 1991-04-17 to 2022-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Tim  Baumhardt et al → SCREENING PLANT-RENTAL; 2023-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** J&J Baumhardt Aggregates → SCREENING PLANT-RENTAL; 2025-03-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tim  Baumhardt et al → J&J Baumhardt Aggregates; 2025-03-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Brian  Baumhardt et al → J&J Baumhardt Aggregates; 2025-03-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John  Baumhardt → J&J Baumhardt Aggregates; 2025-03-17 to 2022-12-31; source msha-controller-operator-history