# Relationship history for MSHA mine 1800316

Current hierarchy: **Chaney Enterprises LP → Chaney Enterprises Lp → LEONARDTOWN SAND & GRAVEL CO.**

- 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:** Leonardtown Sand & Gravel Company → LEONARDTOWN SAND & GRAVEL CO.; 1950-01-01 to 1992-12-17; source msha-controller-operator-history
- **controller_controls_mine:** Chaney Enterprises LP → LEONARDTOWN SAND & GRAVEL CO.; 1950-01-01 to 1992-12-17; source msha-controller-operator-history
- **controller_controls_operator:** Chaney Enterprises LP → Leonardtown Sand & Gravel Company; 1950-01-01 to 1992-12-17; source msha-controller-operator-history
- **controller_controls_mine:** Chaney Enterprises LP → LEONARDTOWN SAND & GRAVEL CO.; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Chaney Enterprises Lp → LEONARDTOWN SAND & GRAVEL CO.; 1992-12-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Chaney Enterprises LP → Chaney Enterprises Lp; 1992-12-18 to current/open; source msha-controller-operator-history