# Relationship history for MSHA mine 3901309

Current hierarchy: **Newman Ralph D → Black Hills Lumber & Stone → #1 Open 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:** Black Hills Lumber & Stone → #1 Open Pit; 1984-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Newman Ralph D → #1 Open Pit; 1984-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Newman Ralph D → Black Hills Lumber & Stone; 1984-10-01 to current/open; source msha-controller-operator-history