# Relationship history for MSHA mine 2103191

Current hierarchy: **Robert J Schwartz; Timothy W Schwartz; Deborah J Cleven; David D Schwart → William J Schwartz & Sons Inc → Washing Plant**

- 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

- **controller_controls_mine:** Timothy W Schwartz et al → Washing Plant; 1983-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** William J Schwartz & Sons Inc → Washing Plant; 1999-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Timothy W Schwartz et al → William J Schwartz & Sons Inc; 1999-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Deborah J Cleven et al → William J Schwartz & Sons Inc; 1999-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert J Schwartz et al → William J Schwartz & Sons Inc; 1999-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David D Schwartz et al → William J Schwartz & Sons Inc; 1999-03-01 to current/open; source msha-controller-operator-history