# Relationship history for MSHA mine 3200131

Current hierarchy: **Aggregate Industries PLC → Camas Minndak Inc → ANDERSON PIT**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Anderson Sand & Gravel Inc → ANDERSON PIT; 1950-01-01 to 1989-04-30; source msha-controller-operator-history
- **controller_controls_mine:** Robert  Weber → ANDERSON PIT; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert  Weber → Anderson Sand & Gravel Inc; 1950-01-01 to 1989-04-30; source msha-controller-operator-history
- **controller_controls_mine:** Kost Brothers Inc → ANDERSON PIT; 1988-08-09 to 1994-02-28; source msha-controller-operator-history
- **operator_operates_mine:** Sheyenne Sand & Gravel Inc → ANDERSON PIT; 1989-05-01 to 1994-02-28; source msha-controller-operator-history
- **controller_controls_operator:** Kost Brothers Inc → Sheyenne Sand & Gravel Inc; 1989-05-01 to 1994-02-28; source msha-controller-operator-history
- **operator_operates_mine:** Camas Minndak Inc → ANDERSON PIT; 1994-03-01 to 1997-05-13; source msha-controller-operator-history
- **controller_controls_mine:** Camas Plc → ANDERSON PIT; 1994-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Camas Plc → Camas Minndak Inc; 1994-03-01 to 1997-05-13; source msha-controller-operator-history
- **operator_operates_mine:** Camas Minndak Inc → ANDERSON PIT; 1997-05-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Aggregate Industries PLC → ANDERSON PIT; 1997-05-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Aggregate Industries PLC → Camas Minndak Inc; 1997-05-14 to current/open; source msha-controller-operator-history