# Relationship history for MSHA mine 2902507

Current hierarchy: **Melissa S  Grossetete; Nugget Sean  Grossetete → Enviroworks LLC → Mountainair**

- 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

- **operator_operates_mine:** Enviroworks LLC → Mountainair; 2019-01-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Melissa S  Grossetete et al → Mountainair; 2019-01-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Melissa S  Grossetete et al → Enviroworks LLC; 2019-01-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Nugget Sean  Grossetete et al → Enviroworks LLC; 2019-01-28 to current/open; source msha-controller-operator-history