# Relationship history for MSHA mine 4503598

Current hierarchy: **Jason  Messmer; Randy  Rognlin → Northwest Rock Inc → Studer 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

- **controller_controls_mine:** John D  Friend et al → Studer Pit; 1950-01-01 to 2006-02-28; source msha-controller-operator-history
- **controller_controls_mine:** Randy  Rognlin → Studer Pit; 2006-03-01 to 2017-12-28; source msha-controller-operator-history
- **operator_operates_mine:** Northwest Rock Inc → Studer Pit; 2006-04-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John D  Friend et al → Northwest Rock Inc; 2006-04-21 to 2006-02-28; source msha-controller-operator-history
- **controller_controls_operator:** Randy  Rognlin → Northwest Rock Inc; 2006-04-21 to 2017-12-28; source msha-controller-operator-history
- **controller_controls_mine:** Randy  Rognlin et al → Studer Pit; 2017-12-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Randy  Rognlin et al → Northwest Rock Inc; 2017-12-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jason  Messmer et al → Northwest Rock Inc; 2017-12-29 to current/open; source msha-controller-operator-history