# Relationship history for MSHA mine 3003206

Current hierarchy: **Patrick O  Armstrong → Armstrong Trucking → South Ti Sand & Gravel**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Armstrong Trucking → South Ti Sand & Gravel; 1997-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Patrick O  Armstrong → South Ti Sand & Gravel; 1997-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Patrick O  Armstrong → Armstrong Trucking; 1997-10-01 to current/open; source msha-controller-operator-history