# Relationship history for MSHA mine 4102903

Current hierarchy: **Chambco Inc-Adams Equipment Co → Brazos Construction Materials → Brazos Construction Materials-Plant E**

- 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:** Fairway Materials Inc → Brazos Construction Materials-Plant E; 1979-01-01 to 1979-10-29; source msha-controller-operator-history
- **controller_controls_mine:** Straughan William → Brazos Construction Materials-Plant E; 1979-01-01 to 1979-10-29; source msha-controller-operator-history
- **controller_controls_operator:** Straughan William → Fairway Materials Inc; 1979-01-01 to 1979-10-29; source msha-controller-operator-history
- **controller_controls_mine:** Chambco Inc-Adams Equipment Co Et Al → Brazos Construction Materials-Plant E; 1979-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Brazos Construction Materials → Brazos Construction Materials-Plant E; 1979-10-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Chambco Inc-Adams Equipment Co Et Al → Brazos Construction Materials; 1979-10-30 to current/open; source msha-controller-operator-history