# Relationship history for MSHA mine 0504369

Current hierarchy: **Stafford Stan → Valley Stone Company → Valley 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Valley Stone Company → Valley Stone Company; 1988-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Stafford Stan → Valley Stone Company; 1988-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Stafford Stan → Valley Stone Company; 1988-06-01 to current/open; source msha-controller-operator-history