# Relationship history for MSHA mine 5400061

Current hierarchy: **United States Government → Maunabo Sand & Gravel → Gravero Palo Seco**

- 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:** Maunabo Sand & Gravel Inc → Gravero Palo Seco; 1950-01-01 to 1991-07-07; source msha-controller-operator-history
- **controller_controls_mine:** Leon Leonardo → Gravero Palo Seco; 1950-01-01 to 1991-07-07; source msha-controller-operator-history
- **controller_controls_operator:** Leon Leonardo → Maunabo Sand & Gravel Inc; 1950-01-01 to 1991-07-07; source msha-controller-operator-history
- **operator_operates_mine:** Maunabo Sand & Gravel Inc → Gravero Palo Seco; 1991-07-08 to 1994-02-14; source msha-controller-operator-history
- **controller_controls_mine:** Torres Roberto → Gravero Palo Seco; 1991-07-08 to 1994-02-14; source msha-controller-operator-history
- **controller_controls_operator:** Torres Roberto → Maunabo Sand & Gravel Inc; 1991-07-08 to 1994-02-14; source msha-controller-operator-history
- **operator_operates_mine:** Maunabo Sand & Gravel → Gravero Palo Seco; 1994-02-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** United States Government → Gravero Palo Seco; 1994-02-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** United States Government → Maunabo Sand & Gravel; 1994-02-15 to current/open; source msha-controller-operator-history