# Relationship history for MSHA mine 3901520

Current hierarchy: **David M  Simpson; Mark A  Simpson → Apple Springs Inc → Apple Springs (Mobile)**

- 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:** Apple Springs Inc → Apple Springs (Mobile); 2007-11-12 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mark A  Simpson  et al → Apple Springs (Mobile); 2007-11-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mark A  Simpson  et al → Apple Springs Inc; 2007-11-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David M  Simpson  et al → Apple Springs Inc; 2007-11-12 to current/open; source msha-controller-operator-history