# Relationship history for MSHA mine 1002110

Current hierarchy: **Lonnie E  Simpson → Debco Construction → Portable Operations**

- 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:** Debco Construction → Portable Operations; 2007-04-11 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Lonnie E  Simpson → Portable Operations; 2007-04-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lonnie E  Simpson → Debco Construction; 2007-04-11 to current/open; source msha-controller-operator-history