# Relationship history for MSHA mine 0504022

Current hierarchy: **Morgan County - Co → Morgan County Highway → PORTABLE PLANT #12**

- 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:** Morgan County - Co → PORTABLE PLANT #12; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Morgan County Highway → PORTABLE PLANT #12; 1985-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Morgan County - Co → Morgan County Highway; 1985-09-01 to current/open; source msha-controller-operator-history