# Relationship history for MSHA mine 0600544

Current hierarchy: **Peburn Sand & Gravel Co Inc → Peburn Sand & Gravel Co Inc → Squash Hollow Pit**

- 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:** Peburn Sand & Gravel Co Inc → Squash Hollow Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Peburn Sand & Gravel Co Inc → Squash Hollow Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Peburn Sand & Gravel Co Inc → Peburn Sand & Gravel Co Inc; 1950-01-01 to current/open; source msha-controller-operator-history