# Relationship history for MSHA mine 4700992

Current hierarchy: **Kurt  Bechthold → Payne & Dolan Inc → State Sand & Gravel Wash Plant**

- 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:** State Sand & Gravel Company → State Sand & Gravel Wash Plant; 1950-01-01 to 1987-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Richard  Glynn → State Sand & Gravel Wash Plant; 1950-01-01 to 1987-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Richard  Glynn → State Sand & Gravel Company; 1950-01-01 to 1987-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Kurt  Bechthold et al → State Sand & Gravel Wash Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Payne & Dolan Inc → State Sand & Gravel Wash Plant; 1987-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kurt  Bechthold et al → Payne & Dolan Inc; 1987-04-01 to current/open; source msha-controller-operator-history