# Relationship history for MSHA mine 1900277

Current hierarchy: **John  Donovan → J Donovan & Son Inc → LEE 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:** J Donovan & Son Inc → LEE PLANT; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** John  Donovan → LEE PLANT; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John  Donovan → J Donovan & Son Inc; 1950-01-01 to current/open; source msha-controller-operator-history