# Relationship history for MSHA mine 3608839

Current hierarchy: **David D  Svonavec → Svonavec Inc → Milford Mine**

- 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:** David D  Svonavec et al → Milford Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Svonavec Inc → Milford Mine; 1999-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David D  Svonavec et al → Svonavec Inc; 1999-12-01 to current/open; source msha-controller-operator-history