Great Western Bank Routing Number: First Interstate Transition Guide

What is the Great Western Bank routing number?

The Great Western Bank routing number is 091408598. This routing number was used for ACH transfers, direct deposits, and electronic fund transfers at Great Western Bank before its merger with First Interstate Bank.

Great Western Bank was a South Dakota-based regional bank that operated across multiple midwestern states. In 2022, First Interstate BancSystem completed its acquisition of Great Western Bank, consolidating operations under the First Interstate brand.

Great Western Bank and First Interstate merger

Following the merger, former Great Western Bank accounts were transitioned to First Interstate Bank. Your routing number may have changed as part of this conversion. Contact First Interstate Bank to confirm your current routing number and account details.

First Interstate Bank continues to serve former Great Western Bank customers at legacy branch locations throughout the Midwest, including South Dakota, Iowa, Nebraska, and surrounding states.

Great Western Bank direct deposit

If you previously used routing number 091408598 for direct deposit, verify with First Interstate Bank whether a new routing number has been assigned to your account following the merger.

Update your direct deposit information with your employer by providing your current First Interstate Bank routing number and account number to ensure uninterrupted payroll and benefit payments.

Great Western Bank wire transfers

Wire transfer instructions for former Great Western Bank accounts may have changed after the First Interstate acquisition. Contact First Interstate Bank for current wire transfer routing details and procedures.

First Interstate Bank maintains full wire transfer capabilities including domestic and international wires. Reach out to your local branch for current cutoff times, fees, and processing information.

Business banking with Slash

Great Western Bank served midwestern businesses before merging with First Interstate. For businesses seeking a modern digital alternative, Slash provides instant ACH and wire transfers, unlimited virtual cards, and automated expense management.

Slash helps businesses move beyond branch-based banking with real-time cash flow visibility, multi-user financial controls, and seamless accounting integrations from a single platform.