# Relationship history for MSHA mine 3606522

Current hierarchy: **Herman Q  Wright; John P  Dixon → Wright Contracting Company → William Penn Stripping**

- 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:** Wright Contracting Company → William Penn Stripping; 1977-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Herman Q  Wright et al → William Penn Stripping; 1977-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Herman Q  Wright et al → Wright Contracting Company; 1977-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John P  Dixon et al → Wright Contracting Company; 1977-10-01 to current/open; source msha-controller-operator-history