# Relationship history for MSHA mine 0504428

Current hierarchy: **Dean H  Craft → Suburban Sand & Gravel → R.J. Campbell's Pit #1**

- 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:** Aggregate Inc → R.J. Campbell's Pit #1; 1990-05-01 to 2004-01-03; source msha-controller-operator-history
- **controller_controls_mine:** Bartz Russell → R.J. Campbell's Pit #1; 1990-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bartz Russell → Aggregate Inc; 1990-05-01 to 2004-01-03; source msha-controller-operator-history
- **operator_operates_mine:** Suburban Sand & Gravel → R.J. Campbell's Pit #1; 2004-01-04 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Dean H  Craft → R.J. Campbell's Pit #1; 2004-01-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dean H  Craft → Suburban Sand & Gravel; 2004-01-04 to current/open; source msha-controller-operator-history