# Relationship history for MSHA mine 2001887

Current hierarchy: **David J  Crimmins; Roger C  Crimmins → A Lindberg & Sons, Inc. → A. Lindberg & Sons, Inc.- Drill Operation 1**

- 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:** Roger C  Crimmins et al → A. Lindberg & Sons, Inc.- Drill Operatio; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Krygoski Construction Company → A. Lindberg & Sons, Inc.- Drill Operatio; 1950-01-01 to 1980-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Krygoski Joseph → A. Lindberg & Sons, Inc.- Drill Operatio; 1950-01-01 to 1980-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Krygoski Joseph → Krygoski Construction Company; 1950-01-01 to 1980-03-31; source msha-controller-operator-history
- **operator_operates_mine:** A Lindberg & Sons Inc → A. Lindberg & Sons, Inc.- Drill Operatio; 1980-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Roger C  Crimmins et al → A Lindberg & Sons Inc; 1980-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David J  Crimmins et al → A Lindberg & Sons Inc; 1980-04-01 to current/open; source msha-controller-operator-history