# Relationship history for MSHA mine 2200111

Current hierarchy: **Granite Construction Inc → Dickerson & Bowen Inc → RIVERSIDE GRAVEL - MCCOMB**

- 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

- **operator_operates_mine:** Riverside Gravel Company → RIVERSIDE GRAVEL - MCCOMB; 1950-01-01 to 1987-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Harold P  Hammett Jr  et al → RIVERSIDE GRAVEL - MCCOMB; 1950-01-01 to 1987-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Harold P  Hammett Jr  et al → Riverside Gravel Company; 1950-01-01 to 1987-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Lester  Williams et al → RIVERSIDE GRAVEL - MCCOMB; 1983-03-01 to 2024-07-31; source msha-controller-operator-history
- **operator_operates_mine:** Dickerson & Bowen Inc → RIVERSIDE GRAVEL - MCCOMB; 1987-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lester  Williams et al → Dickerson & Bowen Inc; 1987-06-01 to 2024-07-31; source msha-controller-operator-history
- **controller_controls_mine:** Granite Construction Inc → RIVERSIDE GRAVEL - MCCOMB; 2024-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Granite Construction Inc → Dickerson & Bowen Inc; 2024-08-01 to current/open; source msha-controller-operator-history