# Relationship history for MSHA mine 4300534

Current hierarchy: **Douglas  Dorr; Donald  Dorr → Dorr Sand & Gravel → DORR 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:** Dorr Sand & Gravel → DORR PIT; 1999-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Donald  Dorr  et al → DORR PIT; 1999-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Donald  Dorr  et al → Dorr Sand & Gravel; 1999-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Douglas  Dorr  et al → Dorr Sand & Gravel; 1999-08-01 to current/open; source msha-controller-operator-history