# Relationship history for MSHA mine 3503795

Current hierarchy: **Gary E  Tryon → Tri Agg Inc. → Portable 2**

- 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:** Gary E  Tryon → Portable 2; 1988-08-11 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Tri Agg Inc. → Portable 2; 2013-04-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gary E  Tryon → Tri Agg Inc.; 2013-04-30 to current/open; source msha-controller-operator-history