# Relationship history for MSHA mine 3900905

Current hierarchy: **Floyd  Obenauer → Obenauer Sand- Gravel- Const → Obenauer Sand- Gravel- Const**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Obenauer Sand- Gravel- Const → Obenauer Sand- Gravel- Const; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Floyd  Obenauer → Obenauer Sand- Gravel- Const; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Floyd  Obenauer → Obenauer Sand- Gravel- Const; 1950-01-01 to current/open; source msha-controller-operator-history