# Relationship history for MSHA mine 2002347

Current hierarchy: **T A  Forsberg → Traverse Asphalt Paving Inc → Walton Pit & Mill**

- 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:** Traverse City Sand & Gravel Inc → Walton Pit & Mill; 1950-01-01 to 1986-06-03; source msha-controller-operator-history
- **controller_controls_mine:** Niedzielski David L → Walton Pit & Mill; 1950-01-01 to 1986-06-03; source msha-controller-operator-history
- **controller_controls_operator:** Niedzielski David L → Traverse City Sand & Gravel Inc; 1950-01-01 to 1986-06-03; source msha-controller-operator-history
- **operator_operates_mine:** Traverse Asphalt Paving Inc → Walton Pit & Mill; 1986-06-04 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** T A  Forsberg → Walton Pit & Mill; 1986-06-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** T A  Forsberg → Traverse Asphalt Paving Inc; 1986-06-04 to current/open; source msha-controller-operator-history