# Relationship history for MSHA mine 3607068

Current hierarchy: **Sharkan Joseph G → Pennsylvania Perlite Corp → Pennsylvania Perlite Corporation**

- 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:** Pennsylvania Perlite Corp → Pennsylvania Perlite Corporation; 1980-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Sharkan Joseph G → Pennsylvania Perlite Corporation; 1980-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sharkan Joseph G → Pennsylvania Perlite Corp; 1980-11-01 to current/open; source msha-controller-operator-history