# Relationship history for MSHA mine 3503420

Current hierarchy: **David J  Davidson; Jerald M  Davidson → J Davidson & Sons Construction Company Inc → Plant 2 J Davidson & Sons Const Co Inc**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** David J  Davidson  et al → Plant 2 J Davidson & Sons Const Co Inc; 1987-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** J Davidson & Sons Construction Company Inc → Plant 2 J Davidson & Sons Const Co Inc; 1995-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David J  Davidson  et al → J Davidson & Sons Construction Company Inc; 1995-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jerald M  Davidson  et al → J Davidson & Sons Construction Company Inc; 1995-06-01 to current/open; source msha-controller-operator-history