# Relationship history for MSHA mine 3200695

Current hierarchy: **Halvorson Randy → Central Contracting Company → Portable Crusher**

- 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

- **controller_controls_mine:** Halvorson Gale → Portable Crusher; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Halvorson Construction Company → Portable Crusher; 1985-08-01 to 1989-06-19; source msha-controller-operator-history
- **controller_controls_operator:** Halvorson Gale → Halvorson Construction Company; 1985-08-01 to 1989-06-19; source msha-controller-operator-history
- **operator_operates_mine:** Central Contracting Company → Portable Crusher; 1989-06-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Halvorson Randy → Portable Crusher; 1989-06-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Halvorson Randy → Central Contracting Company; 1989-06-20 to current/open; source msha-controller-operator-history