# Relationship history for MSHA mine 1901272

Current hierarchy: **Alston J  Potter; Ronald G  Potter; Len F  Potter → AJ Potter Jr & Sons, Inc. → Portable Crusher**

- 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:** AJ Potter Jr & Sons, Inc. → Portable Crusher; 2017-07-03 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Alston J  Potter et al → Portable Crusher; 2017-07-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Alston J  Potter et al → AJ Potter Jr & Sons, Inc.; 2017-07-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ronald G  Potter et al → AJ Potter Jr & Sons, Inc.; 2017-07-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Len F  Potter et al → AJ Potter Jr & Sons, Inc.; 2017-07-03 to current/open; source msha-controller-operator-history