# Relationship history for MSHA mine 3503463

Current hierarchy: **William J  Avison; Michael  Cole → Avison Lumber Company → Avison Rock Quarry**

- 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:** Avison Lumber Company → Avison Rock Quarry; 1998-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Michael  Cole  et al → Avison Rock Quarry; 1998-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael  Cole  et al → Avison Lumber Company; 1998-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William J  Avison et al → Avison Lumber Company; 1998-04-01 to current/open; source msha-controller-operator-history