# Relationship history for MSHA mine 3610305

Current hierarchy: **William M  Ruark → Meshoppen Stone Inc. → PORTABLE CRUSHER 6**

- 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:** William M  Ruark → PORTABLE CRUSHER 6; 1987-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Meshoppen Stone Inc. → PORTABLE CRUSHER 6; 2019-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William M  Ruark → Meshoppen Stone Inc.; 2019-07-01 to current/open; source msha-controller-operator-history