# Relationship history for MSHA mine 3609796

Current hierarchy: **Scott R  Middendorf; Christopher L  Roof → M.R. DIRT INC → Ober 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:** Frank S  Lopke → Ober Quarry; 1950-01-01 to 2021-01-29; source msha-controller-operator-history
- **controller_controls_mine:** Christopher L  Roof et al → Ober Quarry; 2008-05-12 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** M R Dirt → Ober Quarry; 2009-10-13 to 2010-12-01; source msha-controller-operator-history
- **controller_controls_operator:** Christopher L  Roof et al → M R Dirt; 2009-10-13 to 2010-12-01; source msha-controller-operator-history
- **controller_controls_operator:** Scott R  Middendorf et al → M R Dirt; 2009-10-13 to 2010-12-01; source msha-controller-operator-history
- **operator_operates_mine:** F.S. Lopke Contracting, Inc. → Ober Quarry; 2010-12-02 to 2024-02-27; source msha-controller-operator-history
- **controller_controls_operator:** Frank S  Lopke → F.S. Lopke Contracting, Inc.; 2010-12-02 to 2021-01-29; source msha-controller-operator-history
- **controller_controls_mine:** Estate of Frank S Lopke → Ober Quarry; 2021-01-30 to 2022-10-31; source msha-controller-operator-history
- **controller_controls_operator:** Estate of Frank S Lopke → F.S. Lopke Contracting, Inc.; 2021-01-30 to 2022-10-31; source msha-controller-operator-history
- **controller_controls_mine:** Steven  Gregg et al → Ober Quarry; 2022-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Steven  Gregg et al → F.S. Lopke Contracting, Inc.; 2022-11-01 to 2024-02-27; source msha-controller-operator-history
- **controller_controls_operator:** Barbara A Lopke et al → F.S. Lopke Contracting, Inc.; 2022-11-01 to 2024-02-27; source msha-controller-operator-history
- **operator_operates_mine:** M.R. DIRT INC → Ober Quarry; 2024-02-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Scott R  Middendorf et al → M.R. DIRT INC; 2024-02-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Christopher L  Roof et al → M.R. DIRT INC; 2024-02-28 to current/open; source msha-controller-operator-history