# Relationship history for MSHA mine 3608521

Current hierarchy: **Darryl M  Jacobs → Seven Sisters Mining Company, Inc. → Smeltzer 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:** Darryl M  Jacobs → Smeltzer Mine; 1978-08-14 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Seven Sisters Mining Company, Inc. → Smeltzer Mine; 1995-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Darryl M  Jacobs → Seven Sisters Mining Company, Inc.; 1995-07-01 to current/open; source msha-controller-operator-history