# Relationship history for MSHA mine 3609931

Current hierarchy: **Scott R  Middendorf; Christopher L  Roof → M.R. Dirt Inc. → Camptown Quarry**

- 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:** Scott R  Middendorf et al → Camptown Quarry; 2008-05-12 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** M.R. Dirt Inc. → Camptown Quarry; 2011-05-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Scott R  Middendorf et al → M.R. Dirt Inc.; 2011-05-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Christopher L  Roof et al → M.R. Dirt Inc.; 2011-05-24 to current/open; source msha-controller-operator-history