# Relationship history for MSHA mine 2301988

Current hierarchy: **Walter E  Snyder → Plattin Valley Sand & Gravel → Plattin Valley Sand & Gravel**

- 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:** Axtetter & Howard Inc → Plattin Valley Sand & Gravel; 1988-05-01 to 1990-04-08; source msha-controller-operator-history
- **controller_controls_mine:** Robert  Howard → Plattin Valley Sand & Gravel; 1988-05-01 to 1990-04-08; source msha-controller-operator-history
- **controller_controls_operator:** Robert  Howard → Axtetter & Howard Inc; 1988-05-01 to 1990-04-08; source msha-controller-operator-history
- **operator_operates_mine:** Axtetter & Battles Inc → Plattin Valley Sand & Gravel; 1990-04-09 to 1996-05-06; source msha-controller-operator-history
- **controller_controls_mine:** Fred Stuart  Battles → Plattin Valley Sand & Gravel; 1990-04-09 to 1996-05-06; source msha-controller-operator-history
- **controller_controls_operator:** Fred Stuart  Battles → Axtetter & Battles Inc; 1990-04-09 to 1996-05-06; source msha-controller-operator-history
- **operator_operates_mine:** Plattin Valley Sand & Gravel → Plattin Valley Sand & Gravel; 1996-05-07 to 2002-08-18; source msha-controller-operator-history
- **controller_controls_mine:** Walter E  Snyder → Plattin Valley Sand & Gravel; 1996-05-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Walter E  Snyder → Plattin Valley Sand & Gravel; 1996-05-07 to 2002-08-18; source msha-controller-operator-history
- **operator_operates_mine:** Best Sand & Gravel Inc. → Plattin Valley Sand & Gravel; 2002-08-19 to 2004-01-31; source msha-controller-operator-history
- **controller_controls_mine:** Glenn  Johner → Plattin Valley Sand & Gravel; 2002-08-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Glenn  Johner → Best Sand & Gravel Inc.; 2002-08-19 to 2004-01-31; source msha-controller-operator-history
- **operator_operates_mine:** Plattin Valley Sand & Gravel → Plattin Valley Sand & Gravel; 2004-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Walter E  Snyder → Plattin Valley Sand & Gravel; 2004-02-01 to current/open; source msha-controller-operator-history