# Relationship history for MSHA mine 1516041

Current hierarchy: **Robert L  Rosencrans → Sturgeon Mining Co., Inc. → Sturgeon #3**

- 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:** Robert L  Rosencrans et al → Sturgeon #3; 1981-02-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Sturgeon Mining Co., Inc. → Sturgeon #3; 1987-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert L  Rosencrans et al → Sturgeon Mining Co., Inc.; 1987-05-01 to current/open; source msha-controller-operator-history