# Relationship history for MSHA mine 4701468

Current hierarchy: **Robert H  Brown → Baraboo Concrete Company Inc → Brown Pit 2  #70**

- 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:** Baraboo Concrete Company Inc → Brown Pit 2  #70; 1950-01-01 to 1981-04-23; source msha-controller-operator-history
- **controller_controls_mine:** Robert H  Brown → Brown Pit 2  #70; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert H  Brown → Baraboo Concrete Company Inc; 1950-01-01 to 1981-04-23; source msha-controller-operator-history
- **controller_controls_mine:** Larry  Burcalow → Brown Pit 2  #70; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Yahara Materials Inc → Brown Pit 2  #70; 1981-04-24 to 1982-10-28; source msha-controller-operator-history
- **controller_controls_operator:** Larry  Burcalow → Yahara Materials Inc; 1981-04-24 to 1982-10-28; source msha-controller-operator-history
- **operator_operates_mine:** Baraboo Concrete Company Inc → Brown Pit 2  #70; 1982-10-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert H  Brown → Baraboo Concrete Company Inc; 1982-10-29 to current/open; source msha-controller-operator-history