# Relationship history for MSHA mine 0404332

Current hierarchy: **Hartnett Robin & Charles W Poss Iii → Robuck Construction Inc → Robuck/Schmidt Quarry**

- 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:** Schmidt Nancy → Robuck/Schmidt Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Schmidt Construction Inc → Robuck/Schmidt Quarry; 1979-07-01 to 1989-09-05; source msha-controller-operator-history
- **controller_controls_operator:** Schmidt Nancy → Schmidt Construction Inc; 1979-07-01 to 1989-09-05; source msha-controller-operator-history
- **operator_operates_mine:** South Coast Mining & Milling Inc → Robuck/Schmidt Quarry; 1989-09-06 to 1992-11-15; source msha-controller-operator-history
- **controller_controls_mine:** Frank R  Walker Jr → Robuck/Schmidt Quarry; 1989-09-06 to 1992-11-15; source msha-controller-operator-history
- **controller_controls_operator:** Frank R  Walker Jr → South Coast Mining & Milling Inc; 1989-09-06 to 1992-11-15; source msha-controller-operator-history
- **operator_operates_mine:** Robuck Construction Inc → Robuck/Schmidt Quarry; 1992-11-16 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hartnett Robin & Charles W Poss Iii → Robuck/Schmidt Quarry; 1992-11-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hartnett Robin & Charles W Poss Iii → Robuck Construction Inc; 1992-11-16 to current/open; source msha-controller-operator-history