# Relationship history for MSHA mine 4702788

Current hierarchy: **Hofferber James P & John Thomas → James P Hofferber Construction → Portable Crusher #1**

- 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:** James P Hofferber Construction → Portable Crusher #1; 1985-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hofferber James P & John Thomas → Portable Crusher #1; 1985-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hofferber James P & John Thomas → James P Hofferber Construction; 1985-06-01 to current/open; source msha-controller-operator-history