# Relationship history for MSHA mine 2700499

Current hierarchy: **Keith A  Babb → K & B Crushing Equipment, LLC → Hartl**

- 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:** Keith A  Babb → Hartl; 2001-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** K & B Crushing Equipment, LLC → Hartl; 2016-05-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Keith A  Babb → K & B Crushing Equipment, LLC; 2016-05-20 to current/open; source msha-controller-operator-history