# Relationship history for MSHA mine 1302250

Current hierarchy: **Richard  Reimers → Cohrs Construction Inc → PORTABLE SCREENER #1**

- 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:** Bernie  Cohrs  et al → PORTABLE SCREENER #1; 1985-05-01 to 2016-06-12; source msha-controller-operator-history
- **operator_operates_mine:** Cohrs Construction Inc → PORTABLE SCREENER #1; 2000-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bernie  Cohrs  et al → Cohrs Construction Inc; 2000-08-01 to 2016-06-12; source msha-controller-operator-history
- **controller_controls_mine:** Richard  Reimers → PORTABLE SCREENER #1; 2016-06-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Richard  Reimers → Cohrs Construction Inc; 2016-06-13 to current/open; source msha-controller-operator-history