# Relationship history for MSHA mine 1901226

Current hierarchy: **Joseph F Shay → Milford Stone Company → Milford Stone Company**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Joseph F Shay → Milford Stone Company; 2005-07-28 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Milford Stone Company → Milford Stone Company; 2012-04-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Joseph F Shay → Milford Stone Company; 2012-04-09 to current/open; source msha-controller-operator-history