# Relationship history for MSHA mine 1401430

Current hierarchy: **L A  Knebler → L A Knebler Construction Company Inc → 63rd Street Sand 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:** Bradburn Sand Company → 63rd Street Sand Pit; 1983-04-01 to 1983-07-31; source msha-controller-operator-history
- **controller_controls_mine:** Bradburn Kenneth → 63rd Street Sand Pit; 1983-04-01 to 1983-07-31; source msha-controller-operator-history
- **controller_controls_operator:** Bradburn Kenneth → Bradburn Sand Company; 1983-04-01 to 1983-07-31; source msha-controller-operator-history
- **operator_operates_mine:** L A Knebler Construction Company Inc → 63rd Street Sand Pit; 1983-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** L A  Knebler → 63rd Street Sand Pit; 1983-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** L A  Knebler → L A Knebler Construction Company Inc; 1983-08-01 to current/open; source msha-controller-operator-history