# Relationship history for MSHA mine 2002997

Current hierarchy: **Martin R  Gentner → A3 CRUSHING & AGGREGATE, LLC → Pioneer #1**

- 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

- **operator_operates_mine:** Holz Crushing Inc → Pioneer #1; 1997-04-01 to 2005-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Nancy  Holz → Pioneer #1; 1997-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Nancy  Holz → Holz Crushing Inc; 1997-04-01 to 2005-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Holz  Sand & Gravel LLC → Pioneer #1; 2005-06-01 to 2017-04-09; source msha-controller-operator-history
- **controller_controls_mine:** William J  Holz → Pioneer #1; 2005-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William J  Holz → Holz  Sand & Gravel LLC; 2005-06-01 to 2017-04-09; source msha-controller-operator-history
- **operator_operates_mine:** A3 CRUSHING & AGGREGATE, LLC → Pioneer #1; 2017-04-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Martin R  Gentner → Pioneer #1; 2017-04-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin R  Gentner → A3 CRUSHING & AGGREGATE, LLC; 2017-04-10 to current/open; source msha-controller-operator-history