# Relationship history for MSHA mine 1901212

Current hierarchy: **John D  Duquette → Dukes Sand & Gravel → Dukes 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: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Dukes Sand & Gravel → Dukes Sand & Gravel; 2011-10-19 to 2022-07-19; source msha-controller-operator-history
- **controller_controls_mine:** John D  Duquette → Dukes Sand & Gravel; 2011-10-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John D  Duquette → Dukes Sand & Gravel; 2011-10-19 to 2022-07-19; source msha-controller-operator-history
- **operator_operates_mine:** Dukes Sand & Gravel → Dukes Sand & Gravel; 2022-07-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** John D  Duquette → Dukes Sand & Gravel; 2022-07-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John D  Duquette → Dukes Sand & Gravel; 2022-07-20 to current/open; source msha-controller-operator-history