# Relationship history for MSHA mine 0505034

Current hierarchy: **Mark A  Steen → Colorado Milling Company, LLC → Gold Hill mill**

- 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:** Colorado Milling Company, LLC → Gold Hill mill; 2014-10-30 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mark A  Steen et al → Gold Hill mill; 2014-10-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mark A  Steen et al → Colorado Milling Company, LLC; 2014-10-30 to current/open; source msha-controller-operator-history