# Relationship history for MSHA mine 2102520

Current hierarchy: **Greg  Bruening → Holm Brothers Construction Inc → Oconnor 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

- **operator_operates_mine:** Holm Brothers Construction Inc → Oconnor Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Willard C  Holm → Oconnor Quarry; 1950-01-01 to 2010-07-06; source msha-controller-operator-history
- **controller_controls_operator:** Willard C  Holm → Holm Brothers Construction Inc; 1950-01-01 to 2010-07-06; source msha-controller-operator-history
- **controller_controls_mine:** Greg  Bruening → Oconnor Quarry; 2010-07-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Greg  Bruening → Holm Brothers Construction Inc; 2010-07-07 to current/open; source msha-controller-operator-history