# Relationship history for MSHA mine 4100290

Current hierarchy: **Martin Lang C Jr → Martin Brick Company → Martin Pits & Plant**

- 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:** Martin Brick Company → Martin Pits & Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Martin Lang C Jr → Martin Pits & Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Lang C Jr → Martin Brick Company; 1950-01-01 to current/open; source msha-controller-operator-history