# Relationship history for MSHA mine 4703260

Current hierarchy: **Brian  Baumhardt; Tim  Baumhardt → J & J Baumhardt Aggregates, Inc. → PORTABLE SCREENING PLANT**

- 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 → PORTABLE SCREENING PLANT; 1991-04-17 to 2022-12-31; source msha-controller-operator-history
- **operator_operates_mine:** J & J Baumhardt Aggregates, Inc. → PORTABLE SCREENING PLANT; 2001-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John  Baumhardt → J & J Baumhardt Aggregates, Inc.; 2001-03-01 to 2022-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Tim  Baumhardt et al → PORTABLE SCREENING PLANT; 2023-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tim  Baumhardt et al → J & J Baumhardt Aggregates, Inc.; 2023-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Brian  Baumhardt et al → J & J Baumhardt Aggregates, Inc.; 2023-01-01 to current/open; source msha-controller-operator-history