# Relationship history for MSHA mine 0504533

Current hierarchy: **George W  Hall → Hall-Irwin Construction Company → TUCSON RESOURCES**

- 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:** George W  Hall et al → TUCSON RESOURCES; 1988-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Jones Donald D → TUCSON RESOURCES; 1990-11-01 to 1996-03-28; source msha-controller-operator-history
- **operator_operates_mine:** Material Processing Inc → TUCSON RESOURCES; 1993-10-01 to 1995-04-30; source msha-controller-operator-history
- **controller_controls_operator:** Jones Donald D → Material Processing Inc; 1993-10-01 to 1995-04-30; source msha-controller-operator-history
- **operator_operates_mine:** Hall-Irwin Construction Company → TUCSON RESOURCES; 1995-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** George W  Hall et al → Hall-Irwin Construction Company; 1995-05-01 to current/open; source msha-controller-operator-history