# Relationship history for MSHA mine 1800287

Current hierarchy: **Chaney Enterprises LP → Sustainable Land Use, LLC → Waldorf-MD 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:** Charles County Sand & Gravel Company Inc → Waldorf-MD Sand & Gravel; 1950-01-01 to 1992-12-17; source msha-controller-operator-history
- **controller_controls_mine:** Chaney Enterprises LP → Waldorf-MD Sand & Gravel; 1950-01-01 to 1992-12-17; source msha-controller-operator-history
- **controller_controls_operator:** Chaney Enterprises LP → Charles County Sand & Gravel Company Inc; 1950-01-01 to 1992-12-17; source msha-controller-operator-history
- **controller_controls_mine:** Chaney Enterprises LP → Waldorf-MD Sand & Gravel; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Chaney Enterprises LTD Partnership → Waldorf-MD Sand & Gravel; 1992-12-18 to 2024-03-25; source msha-controller-operator-history
- **controller_controls_operator:** Chaney Enterprises LP → Chaney Enterprises LTD Partnership; 1992-12-18 to 2024-03-25; source msha-controller-operator-history
- **controller_controls_mine:** Chaney Enterprises LP → Waldorf-MD Sand & Gravel; 2024-03-25 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Sustainable Land Use, LLC → Waldorf-MD Sand & Gravel; 2024-03-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Chaney Enterprises LP → Sustainable Land Use, LLC; 2024-03-26 to current/open; source msha-controller-operator-history