# Relationship history for MSHA mine 3003589

Current hierarchy: **Thomas  Poley; Ryan  Calkin → Poley Sand & Gravel → North Branch Sand and Gravel Pit/Zieres**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **controller_controls_mine:** Ryan  Calkin Et Al → North Branch Sand and Gravel Pit/Zieres; 2003-12-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Sipple & Redard Partners → North Branch Sand and Gravel Pit/Zieres; 2007-04-25 to 2008-11-12; source msha-controller-operator-history
- **controller_controls_mine:** Gregg A  Sipple et al → North Branch Sand and Gravel Pit/Zieres; 2007-04-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gregg A  Sipple et al → Sipple & Redard Partners; 2007-04-25 to 2008-11-12; source msha-controller-operator-history
- **controller_controls_operator:** Kenneth G  Redard et al → Sipple & Redard Partners; 2007-04-25 to 2008-11-12; source msha-controller-operator-history
- **operator_operates_mine:** Poley Sand & Gravel → North Branch Sand and Gravel Pit/Zieres; 2008-11-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ryan  Calkin Et Al → Poley Sand & Gravel; 2008-11-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thomas  Poley Et Al → Poley Sand & Gravel; 2008-11-13 to current/open; source msha-controller-operator-history