# Relationship history for MSHA mine 0900389

Current hierarchy: **Farris  Richardson → Richardson Sand Company → Suggs Dredge**

- 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

- **operator_operates_mine:** Garrett Sand Company → Suggs Dredge; 1950-01-01 to 1980-10-16; source msha-controller-operator-history
- **controller_controls_mine:** W E  Garrett → Suggs Dredge; 1950-01-01 to 1980-10-16; source msha-controller-operator-history
- **controller_controls_operator:** W E  Garrett → Garrett Sand Company; 1950-01-01 to 1980-10-16; source msha-controller-operator-history
- **controller_controls_mine:** Farris  Richardson → Suggs Dredge; 1980-08-25 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Richardson Sand Company → Suggs Dredge; 1980-10-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Farris  Richardson → Richardson Sand Company; 1980-10-17 to current/open; source msha-controller-operator-history