# Relationship history for MSHA mine 3200807

Current hierarchy: **Knife River Corporation → Strata Corporation → Portable Plant #7**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** James R  Bradshaw et al → Portable Plant #7; 1950-01-01 to 2026-03-22; source msha-controller-operator-history
- **operator_operates_mine:** Earth Movers, Inc. → Portable Plant #7; 2003-03-24 to 2006-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Jeanne  Gohl  et al → Portable Plant #7; 2003-03-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jeanne  Gohl  et al → Earth Movers, Inc.; 2003-03-24 to 2006-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Russell R  Gohl  et al → Earth Movers, Inc.; 2003-03-24 to 2006-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Strata Corporation → Portable Plant #7; 2006-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James R  Bradshaw et al → Strata Corporation; 2006-07-01 to 2026-03-22; source msha-controller-operator-history
- **controller_controls_mine:** Knife River Corporation → Portable Plant #7; 2026-03-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Knife River Corporation → Strata Corporation; 2026-03-23 to current/open; source msha-controller-operator-history