# Relationship history for MSHA mine 1302217

Current hierarchy: **Summit Materials LLC → NR Hamm Quarry LLC → Knoxville Mine**

- 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:** Greg  Bruening → Knoxville Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** N R  Hamm → Knoxville Mine; 1950-01-01 to 2012-02-08; source msha-controller-operator-history
- **operator_operates_mine:** Bruening Rock Products Inc → Knoxville Mine; 1998-03-01 to 2024-11-24; source msha-controller-operator-history
- **controller_controls_operator:** Greg  Bruening → Bruening Rock Products Inc; 1998-03-01 to 2024-11-24; source msha-controller-operator-history
- **controller_controls_mine:** Summit Materials LLC → Knoxville Mine; 2012-02-09 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** NR Hamm Quarry LLC → Knoxville Mine; 2024-11-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** N R  Hamm → NR Hamm Quarry LLC; 2024-11-25 to 2012-02-08; source msha-controller-operator-history
- **controller_controls_operator:** Summit Materials LLC → NR Hamm Quarry LLC; 2024-11-25 to current/open; source msha-controller-operator-history