# Relationship history for MSHA mine 3303860

Current hierarchy: **Scott C  Slater; Neal  Cotingim → N & S  Sand & Gravel → N & S 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

- **controller_controls_mine:** Schweitzer Roy B → N & S Sand & Gravel; 1979-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** New Miami Sand & Gravel → N & S Sand & Gravel; 1981-04-01 to 1989-10-16; source msha-controller-operator-history
- **controller_controls_mine:** Schmidter William C & James T Schrimpf → N & S Sand & Gravel; 1981-04-01 to 1989-10-16; source msha-controller-operator-history
- **controller_controls_operator:** Schmidter William C & James T Schrimpf → New Miami Sand & Gravel; 1981-04-01 to 1989-10-16; source msha-controller-operator-history
- **operator_operates_mine:** Gravel Company → N & S Sand & Gravel; 1989-10-17 to 2005-06-07; source msha-controller-operator-history
- **controller_controls_operator:** Schweitzer Roy B → Gravel Company; 1989-10-17 to 2005-06-07; source msha-controller-operator-history
- **operator_operates_mine:** N & S  Sand & Gravel → N & S Sand & Gravel; 2005-06-08 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Neal  Cotingim et al → N & S Sand & Gravel; 2005-06-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Neal  Cotingim et al → N & S  Sand & Gravel; 2005-06-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Scott C  Slater et al → N & S  Sand & Gravel; 2005-06-08 to current/open; source msha-controller-operator-history