# Relationship history for MSHA mine 4202050

Current hierarchy: **Granite Construction Inc → Granite Construction Company → Portable Crusher #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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Granite Construction Inc → Portable Crusher #1; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Gibbons Companies → Portable Crusher #1; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Concrete Products Co-Div/Gibbons & Reed Company → Portable Crusher #1; 1989-08-01 to 1996-12-11; source msha-controller-operator-history
- **controller_controls_operator:** Gibbons Companies → Concrete Products Co-Div/Gibbons & Reed Company; 1989-08-01 to 1996-12-11; source msha-controller-operator-history
- **operator_operates_mine:** Granite Construction Company → Portable Crusher #1; 1996-12-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Granite Construction Inc → Granite Construction Company; 1996-12-12 to current/open; source msha-controller-operator-history