# Relationship history for MSHA mine 0801089

Current hierarchy: **Johnson John Marvin Jr → Johnson Sand Company → Johnson Sand Company**

- 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

- **controller_controls_mine:** Johnson John Marvin Jr → Johnson Sand Company; 1981-05-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Johnson Sand Company → Johnson Sand Company; 1988-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Johnson John Marvin Jr → Johnson Sand Company; 1988-02-01 to current/open; source msha-controller-operator-history