# Relationship history for MSHA mine 3901648

Current hierarchy: **Jeff  Opperman → OPPERMAN, INC. → Opperman Portable 1700S**

- 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:** Harlan  Opperman → Opperman Portable 1700S; 1950-01-01 to 2018-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Jeff  Opperman → Opperman Portable 1700S; 2019-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** OPPERMAN, INC. → Opperman Portable 1700S; 2020-05-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jeff  Opperman → OPPERMAN, INC.; 2020-05-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Harlan  Opperman → OPPERMAN, INC.; 2020-05-07 to 2018-12-31; source msha-controller-operator-history