# Relationship history for MSHA mine 3503885

Current hierarchy: **Peter L Billeter → R&M Quarries LLC → Portable Plant**

- 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:** Peter L Billeter → Portable Plant; 2016-04-15 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** R&M Quarries LLC → Portable Plant; 2019-02-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Peter L Billeter → R&M Quarries LLC; 2019-02-13 to current/open; source msha-controller-operator-history