# Relationship history for MSHA mine 1601262

Current hierarchy: **Shaffer David & Verl Holland → H & S Sand & Gravel → H & S**

- 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:** H & S Sand & Gravel → H & S; 1993-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Shaffer David & Verl Holland → H & S; 1993-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Shaffer David & Verl Holland → H & S Sand & Gravel; 1993-06-01 to current/open; source msha-controller-operator-history