# Relationship history for MSHA mine 4702837

Current hierarchy: **Brian  Baumhardt; Tim  Baumhardt → J&J Baumhardt Aggregates → PORTABLE WASH 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Butzke Sand & Gravel Inc → PORTABLE WASH PLANT; 1986-09-01 to 1991-04-16; source msha-controller-operator-history
- **controller_controls_mine:** Marvin  Butzke → PORTABLE WASH PLANT; 1986-09-01 to 1991-04-16; source msha-controller-operator-history
- **controller_controls_operator:** Marvin  Butzke → Butzke Sand & Gravel Inc; 1986-09-01 to 1991-04-16; source msha-controller-operator-history
- **operator_operates_mine:** J&J Baumhardt Aggregates → PORTABLE WASH PLANT; 1991-04-17 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** John  Baumhardt → PORTABLE WASH PLANT; 1991-04-17 to 2022-12-31; source msha-controller-operator-history
- **controller_controls_operator:** John  Baumhardt → J&J Baumhardt Aggregates; 1991-04-17 to 2022-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Brian  Baumhardt et al → PORTABLE WASH PLANT; 2023-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Brian  Baumhardt et al → J&J Baumhardt Aggregates; 2023-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tim  Baumhardt et al → J&J Baumhardt Aggregates; 2023-01-01 to current/open; source msha-controller-operator-history