# Relationship history for MSHA mine 3301549

Current hierarchy: **Colas S A → Barrett Paving Materials Inc → Plant 92**

- 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:** Brewer P J → Plant 92; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Mariemont Sand & Gravel Company → Plant 92; 1950-01-01 to 1979-06-06; source msha-controller-operator-history
- **controller_controls_mine:** Mariemont Sand & Gravel Company → Plant 92; 1950-01-01 to 1979-06-06; source msha-controller-operator-history
- **controller_controls_operator:** Mariemont Sand & Gravel Company → Mariemont Sand & Gravel Company; 1950-01-01 to 1979-06-06; source msha-controller-operator-history
- **operator_operates_mine:** Brewer Company → Plant 92; 1979-06-07 to 1987-05-26; source msha-controller-operator-history
- **controller_controls_operator:** Brewer P J → Brewer Company; 1979-06-07 to 1987-05-26; source msha-controller-operator-history
- **controller_controls_mine:** Colas S A → Plant 92; 1979-12-14 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Barrett Paving Materials Inc → Plant 92; 1987-05-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Colas S A → Barrett Paving Materials Inc; 1987-05-27 to current/open; source msha-controller-operator-history