# Relationship history for MSHA mine 1001908

Current hierarchy: **Fremont County-Id → Fremont County Road & Bridge → PORTABLE SCREENING 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Fremont County Road & Bridge → PORTABLE SCREENING PLANT; 1994-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Fremont County-Id → PORTABLE SCREENING PLANT; 1994-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Fremont County-Id → Fremont County Road & Bridge; 1994-09-01 to current/open; source msha-controller-operator-history