# Relationship history for MSHA mine 3304175

Current hierarchy: **George A Gressner; Sue A Newton → NEWTON ASPHALT → MARINO PIT**

- 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:** Newton Asphalt → MARINO PIT; 1989-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Sue A Newton et al → MARINO PIT; 1989-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sue A Newton et al → Newton Asphalt; 1989-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** George A Gressner et al → Newton Asphalt; 1989-08-01 to current/open; source msha-controller-operator-history