# Relationship history for MSHA mine 1700855

Current hierarchy: **William  Perry → B & C Sand and Gravel, Inc. → B & C Sand and Gravel, Inc.**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** B & C Sand and Gravel, Inc. → B & C Sand and Gravel, Inc.; 2010-08-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** William  Perry → B & C Sand and Gravel, Inc.; 2010-08-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William  Perry → B & C Sand and Gravel, Inc.; 2010-08-10 to current/open; source msha-controller-operator-history