# Relationship history for MSHA mine 0504766

Current hierarchy: **Mark T  Olin → Independant Reliable Services, Inc. → Bay City Crushing**

- 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:** Independant Reliable Services, Inc. → Bay City Crushing; 2003-05-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mark T  Olin → Bay City Crushing; 2003-05-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mark T  Olin → Independant Reliable Services, Inc.; 2003-05-20 to current/open; source msha-controller-operator-history