# Relationship history for MSHA mine 3401946

Current hierarchy: **Don M  Donaho → Donaho Stone LLC → Back Forty**

- 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:** Don M  Donaho et al → Back Forty; 1997-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Donaho Stone → Back Forty; 2004-09-14 to 2013-12-12; source msha-controller-operator-history
- **controller_controls_operator:** Don M  Donaho et al → Donaho Stone; 2004-09-14 to 2013-12-12; source msha-controller-operator-history
- **controller_controls_mine:** Don M  Donaho et al → Back Forty; 2011-03-11 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Donaho Stone LLC → Back Forty; 2013-12-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Don M  Donaho et al → Donaho Stone LLC; 2013-12-13 to current/open; source msha-controller-operator-history