# Relationship history for MSHA mine 1519930

Current hierarchy: **Leonard  Hendrickson → Hendrickson Equipment, Inc. → Merritt Branch**

- 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:** Leonard  Hendrickson → Merritt Branch; 2000-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Hendrickson Equipment, Inc. → Merritt Branch; 2022-10-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Leonard  Hendrickson → Hendrickson Equipment, Inc.; 2022-10-12 to current/open; source msha-controller-operator-history