# Relationship history for MSHA mine 1700928

Current hierarchy: **Samuel S  Sargent → Stockton Sand & Gravel → PMD**

- 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:** Stockton Sand & Gravel → PMD; 2014-04-30 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Samuel S  Sargent → PMD; 2014-04-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Samuel S  Sargent → Stockton Sand & Gravel; 2014-04-30 to current/open; source msha-controller-operator-history