# Relationship history for MSHA mine 3401636

Current hierarchy: **Clayton  Hufnagel → Diamond Gypsum Company → Pit #1 Diamond Gypsum**

- 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:** Diamond Gypsum Company → Pit #1 Diamond Gypsum; 1988-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Clayton  Hufnagel → Pit #1 Diamond Gypsum; 1988-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Clayton  Hufnagel → Diamond Gypsum Company; 1988-01-01 to current/open; source msha-controller-operator-history