# Relationship history for MSHA mine 3503302

Current hierarchy: **Richard  Pearsall → Cascade Pumice Inc → DESCHUTES PLANT**

- 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:** Harbor Resources → DESCHUTES PLANT; 1985-05-15 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Cascade Pumice Inc → DESCHUTES PLANT; 1988-03-01 to 1994-09-30; source msha-controller-operator-history
- **controller_controls_operator:** Harbor Resources → Cascade Pumice Inc; 1988-03-01 to 1994-09-30; source msha-controller-operator-history
- **operator_operates_mine:** Cascade Pumice Inc → DESCHUTES PLANT; 1994-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Richard  Pearsall → DESCHUTES PLANT; 1994-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Richard  Pearsall → Cascade Pumice Inc; 1994-10-01 to current/open; source msha-controller-operator-history