# Relationship history for MSHA mine 3901280

Current hierarchy: **Mother Lode Corp & Iris Company → Ingersoll Mining Company → Bob Ingersoll Mine**

- 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:** Ingersoll Mining Company → Bob Ingersoll Mine; 1981-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mother Lode Corp & Iris Company → Bob Ingersoll Mine; 1981-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mother Lode Corp & Iris Company → Ingersoll Mining Company; 1981-12-01 to current/open; source msha-controller-operator-history