# Relationship history for MSHA mine 2100154

Current hierarchy: **Berkshire Hathaway Inc → Acme-Ochs Brick and Stone Inc → Springfield 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:** Ochs Brick & Tile Company → Springfield Pit; 1950-01-01 to 2008-05-22; source msha-controller-operator-history
- **controller_controls_mine:** Ochs Brick & Tile Company → Springfield Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ochs Brick & Tile Company → Ochs Brick & Tile Company; 1950-01-01 to 2008-05-22; source msha-controller-operator-history
- **operator_operates_mine:** Acme-Ochs Brick and Stone Inc → Springfield Pit; 2008-05-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Berkshire Hathaway Inc → Springfield Pit; 2008-05-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Berkshire Hathaway Inc → Acme-Ochs Brick and Stone Inc; 2008-05-23 to current/open; source msha-controller-operator-history