# Relationship history for MSHA mine 4500632

Current hierarchy: **Jason  Messmer; Randy  Rognlin → Northwest Rock, Inc. → Track Mounted Portable Plant #2**

- 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:** Graystone Of Grays Harbor → Track Mounted Portable Plant #2; 1950-01-01 to 1984-10-25; source msha-controller-operator-history
- **controller_controls_mine:** Graystone Corp → Track Mounted Portable Plant #2; 1950-01-01 to 1984-10-25; source msha-controller-operator-history
- **controller_controls_operator:** Graystone Corp → Graystone Of Grays Harbor; 1950-01-01 to 1984-10-25; source msha-controller-operator-history
- **controller_controls_mine:** John D  Friend et al → Track Mounted Portable Plant #2; 1950-01-01 to 2006-02-28; source msha-controller-operator-history
- **operator_operates_mine:** Peninsula Industries → Track Mounted Portable Plant #2; 1984-10-26 to 1988-05-10; source msha-controller-operator-history
- **controller_controls_mine:** Harbor Resources → Track Mounted Portable Plant #2; 1984-10-26 to 1988-05-10; source msha-controller-operator-history
- **controller_controls_operator:** Harbor Resources → Peninsula Industries; 1984-10-26 to 1988-05-10; source msha-controller-operator-history
- **operator_operates_mine:** Northwest Rock, Inc. → Track Mounted Portable Plant #2; 1988-05-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John D  Friend et al → Northwest Rock, Inc.; 1988-05-11 to 2006-02-28; source msha-controller-operator-history
- **controller_controls_mine:** Randy  Rognlin → Track Mounted Portable Plant #2; 2006-03-01 to 2017-12-28; source msha-controller-operator-history
- **controller_controls_operator:** Randy  Rognlin → Northwest Rock, Inc.; 2006-03-01 to 2017-12-28; source msha-controller-operator-history
- **controller_controls_mine:** Randy  Rognlin et al → Track Mounted Portable Plant #2; 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