# Relationship history for MSHA mine 4104421

Current hierarchy: **Bill  Glass → H & B Contractors Ltd → Hirsch 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:** Bill  Glass → Hirsch Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** H & B Contractors Ltd → Hirsch Pit; 2003-05-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bill  Glass → H & B Contractors Ltd; 2003-05-09 to current/open; source msha-controller-operator-history