# Relationship history for MSHA mine 0901259

Current hierarchy: **Edwin C  Williams → Crystal Blue Quarry Inc. → Crystal Blue Quarries, Inc. TWO**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Walter Allen  Mc Cannon → Crystal Blue Quarries, Inc. TWO; 1950-01-01 to 2022-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Crystal Blue Quarry Inc. → Crystal Blue Quarries, Inc. TWO; 2021-04-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Walter Allen  Mc Cannon → Crystal Blue Quarry Inc.; 2021-04-23 to 2022-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Edwin C  Williams → Crystal Blue Quarries, Inc. TWO; 2023-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Edwin C  Williams → Crystal Blue Quarry Inc.; 2023-01-01 to current/open; source msha-controller-operator-history