# Relationship history for MSHA mine 2901820

Current hierarchy: **Firchau Albert J → Firchau Industries → Arroyo Mine #1**

- 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:** Arroyo Mining Company Inc → Arroyo Mine #1; 1980-05-01 to 1983-08-30; source msha-controller-operator-history
- **controller_controls_mine:** Firchau Albert J → Arroyo Mine #1; 1980-05-01 to 1983-08-30; source msha-controller-operator-history
- **controller_controls_operator:** Firchau Albert J → Arroyo Mining Company Inc; 1980-05-01 to 1983-08-30; source msha-controller-operator-history
- **operator_operates_mine:** Integrated Native Resources Inc → Arroyo Mine #1; 1983-08-31 to 1984-03-19; source msha-controller-operator-history
- **controller_controls_mine:** Peone Charles E → Arroyo Mine #1; 1983-08-31 to 1984-03-19; source msha-controller-operator-history
- **controller_controls_operator:** Peone Charles E → Integrated Native Resources Inc; 1983-08-31 to 1984-03-19; source msha-controller-operator-history
- **operator_operates_mine:** Firchau Industries → Arroyo Mine #1; 1984-03-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Firchau Albert J → Arroyo Mine #1; 1984-03-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Firchau Albert J → Firchau Industries; 1984-03-20 to current/open; source msha-controller-operator-history