# Relationship history for MSHA mine 2003531

Current hierarchy: **Bartley D Tickler → DDT Construction, Inc. → Cedar Rapids**

- 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:** DDT Construction Inc → Cedar Rapids; 2016-05-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bartley D Tickler → Cedar Rapids; 2016-05-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bartley D Tickler → DDT Construction Inc; 2016-05-23 to current/open; source msha-controller-operator-history