# Relationship history for MSHA mine 2103123

Current hierarchy: **Henry B  Thieman → West Central Gravel Inc. → Crusher #1 Pioneer**

- 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

- **controller_controls_mine:** Henry B  Thieman → Crusher #1 Pioneer; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** West Central Gravel Inc. → Crusher #1 Pioneer; 1996-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Henry B  Thieman → West Central Gravel Inc.; 1996-06-01 to current/open; source msha-controller-operator-history