# Relationship history for MSHA mine 3304752

Current hierarchy: **Benjamin  Geddis; Steve R  Oliver → Cornerstone Crushing → Unit 1 Portable Crusher**

- 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:** Benjamin  Geddis et al → Unit 1 Portable Crusher; 2017-02-08 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Cornerstone Crushing → Unit 1 Portable Crusher; 2020-04-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Benjamin  Geddis et al → Cornerstone Crushing; 2020-04-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Steve R  Oliver et al → Cornerstone Crushing; 2020-04-07 to current/open; source msha-controller-operator-history