# Relationship history for MSHA mine 3608558

Current hierarchy: **Leonard A  Rossi → Rossi Excavating Company → Black Ridge**

- 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:** Leonard A  Rossi → Black Ridge; 1983-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Continental Cogeneration Corp (CCC) et al → Black Ridge; 1987-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Continental Energy Associates Lp → Black Ridge; 1996-05-01 to 1996-07-18; source msha-controller-operator-history
- **controller_controls_operator:** Continental Cogeneration Corp (CCC) et al → Continental Energy Associates Lp; 1996-05-01 to 1996-07-18; source msha-controller-operator-history
- **operator_operates_mine:** Rossi Excavating Company → Black Ridge; 1996-07-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Leonard A  Rossi → Rossi Excavating Company; 1996-07-19 to current/open; source msha-controller-operator-history