# Relationship history for MSHA mine 3003289

Current hierarchy: **Hannah L  Robinson → H L Robinson Sand & Gravel Inc → Spencer 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Thomas E  Besemer → Spencer Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hannah L  Robinson → Spencer Pit; 1988-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Cayuga Crushed Stone Inc → Spencer Pit; 1999-06-01 to 2000-07-14; source msha-controller-operator-history
- **controller_controls_operator:** Thomas E  Besemer → Cayuga Crushed Stone Inc; 1999-06-01 to 2000-07-14; source msha-controller-operator-history
- **operator_operates_mine:** H L Robinson Sand & Gravel Inc → Spencer Pit; 2000-07-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hannah L  Robinson → H L Robinson Sand & Gravel Inc; 2000-07-15 to current/open; source msha-controller-operator-history