# Relationship history for MSHA mine 4104203

Current hierarchy: **Melva  Salinas; Edgar  Ramirez → Ramirez Stone & Masonry LLC → El Oso**

- 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:** Ervin Masonry → El Oso; 2000-08-01 to 2018-02-26; source msha-controller-operator-history
- **controller_controls_mine:** Thomas  Ervin → El Oso; 2000-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thomas  Ervin → Ervin Masonry; 2000-08-01 to 2018-02-26; source msha-controller-operator-history
- **operator_operates_mine:** Ramirez Stone & Masonry LLC → El Oso; 2018-02-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Melva  Salinas et al → El Oso; 2018-02-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Melva  Salinas et al → Ramirez Stone & Masonry LLC; 2018-02-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Edgar  Ramirez et al → Ramirez Stone & Masonry LLC; 2018-02-27 to current/open; source msha-controller-operator-history