# Relationship history for MSHA mine 0504028

Current hierarchy: **Vernon  Dilley → Dilley'S Sand & Gravel → Hanson Pit**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Dilley'S Sand & Gravel → Hanson Pit; 1985-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Vernon  Dilley → Hanson Pit; 1985-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Vernon  Dilley → Dilley'S Sand & Gravel; 1985-04-01 to current/open; source msha-controller-operator-history