# Relationship history for MSHA mine 3002515

Current hierarchy: **North Norwich-Ny → Town Of North Norwich → Robert H Stackhouse Pit Or Robert H Stac**

- 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:** Town Of North Norwich → Robert H Stackhouse Pit Or Robert H Stac; 1980-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** North Norwich-Ny → Robert H Stackhouse Pit Or Robert H Stac; 1980-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** North Norwich-Ny → Town Of North Norwich; 1980-05-01 to current/open; source msha-controller-operator-history