Finding the Nearest Branch and ATM is Easy
Whether you are across town or traveling far from home, you are welcome at any of our seven convenient branches in South Dakota and at any of the 5,600 CO-OP Shared Branch locations and the 250 Xtend Shared Branch locations nationwide.
Finding the Nearest Branch and ATM is Easy
Whether you are across town or traveling far from home, you are welcome at any of our seven convenient branches in South Dakota and at any of the 5,600 CO-OP Shared Branch locations and the 250 Xtend Shared Branch locations nationwide.
You can get person-to-person assistance with your accounts and conduct transactions just like you would at your home Credit Union. Just look for the CO-OP Shared Branch and the Xtend Shared Branch logos.
Get cash surcharge-free at more ATMs than ever.* You’ll find nearly 30,000 surcharge-free ATMs with the CO-OP ATM logo. Including locations at places you may shop, such as 7-Eleven® and Costco®.
Sentinel Federal Locations, Hours & ATMs
Call Center
Call Center Hours Mon – Fri 7:30 am – 5:30 pm MT |
Contact Us Main Phone: 605-923-1405 DSN: 675-6303 |
Mailing Address PO Box 700 |
Our Call Center is live and local
We are proud to have live Call Center Representatives available Monday through Friday from 7:30 a.m. to 5:30 p.m. (MT) to answer your calls.
There is no menu to listen to or selections to make. Our Call Center Team will answer the phone and assist you. We believe that your membership with us deserves a personal touch.
Give us a call at 605-923-1405 or 888-923-1400. Our military members can also call us on the Defense Switched Network (DSN) at 675-6303.
Box Elder – Radar Hill Road Branch
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Street Address 22752 Mule Deer Trail |
Mailing Address PO Box 700 |
Drive-Up ATMs 447 North Ellsworth Road 22752 Mule Deer Trail |
Contact Us Main Phone: 605-923-1405 |
Call Center Hours Mon – Fri 7:30 am – 5:30 pm MT |
Lobby Hours Mon – Fri 9:00 am – 4:30 pm MT |
Drive-Up Hours Mon – Fri 8:30 am – 4:30 pm MT |
Custer Branch
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Street Address 18 Mount Rushmore Road |
Mailing Address PO Box 700 |
Drive-Up ATM |
Contact Us Main Phone: 605-923-1405 |
Call Center Hours Mon – Fri 7:30 am – 5:30 pm MT |
Lobby Hours Mon – Fri 9:00 am – 5:00 pm MT |
Drive-Up Hours Mon – Thurs 8:00 am – 5:00 pm MT |
Ellsworth AFB – Main Office
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Street Address 2723 Lemay Blvd |
Mailing Address PO Box 700 |
Drive-Up ATM 2723 Lemay Blvd Walk-Up ATM 2932 Arnold Dr |
Contact Us Main Phone: 605-923-1405 DSN: 675-6303 |
Call Center Hours Mon – Fri 7:30 am – 5:30 pm MT |
Lobby Hours Mon – Fri 9:00 am – 5:00 pm MT |
Hill City Branch
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Street Address 553 E. Main Street |
Mailing Address PO Box 240 |
Contact Us Main Phone: 605-923-1405 |
Call Center Hours Mon – Fri 7:30 am – 5:30 pm MT |
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Lobby Hours Mon – Fri 8:00 am – 5:00 pm MT |
Rapid City – Haines Branch
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Street Address 1430 Haines Ave Ste 101 |
Mailing Address PO Box 700 |
Drive-Up ATM |
Contact Us Main Phone: 605-923-1405 |
Call Center Hours Mon – Fri 7:30 am – 5:30 pm MT |
Lobby Hours Mon – Fri 9:00 am – 5:00 pm MT |
Drive-Up Hours Mon – Fri 7:30 am – 5:30 pm MT Saturday 9:00 am – Noon MT |
Rapid City – Triple Crown Branch
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Street Address 4011 Triple Crown Dr |
Mailing Address PO Box 700 |
Drive-Up ATM |
Contact Us Main Phone: 605-923-1405 |
Call Center Hours Mon – Fri 7:30 am – 5:30 pm MT |
Lobby Hours Mon – Fri 9:00 am – 5:00 pm MT |
Drive-Up Hours Mon – Thurs 8:00 am – 5:00 pm MT |
Winner Branch
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Street Address 511 E 2nd St |
Mailing Address 511 E 2nd St |
Drive-Up ATM
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Contact Us Phone: 605-842-3581 |
Call Center Hours Mon – Fri 7:30 am – 5:30 pm MT |
Lobby Hours Mon – Fri 8:30 am – 3:30 pm CT |
Drive-Up Hours Mon – Fri 8:00 am – 3:30 pm CT |
CO-OP ATM & Shared Branch Locator

From coast to coast, you’re welcome at branches and ATMs wherever you see the CO-OP logos. That covers a lot of territory — whether you’re across town or traveling far from home for business or pleasure. Your credit union membership means you can:
- Use nearly 30,000 surcharge-free* ATM locations — more than some of the biggest banks offer
- Take advantage of surcharge-free ATMs at convenient places like 7-Eleven® and Costco®
- Visit over 5,600 convenient Shared Branch locations covering all 50 states – simply have your credit union name, account number, and a government ID and you’ll have access to your accounts
- Easily locate ATMs and branches through any of our locator tools — including phone, mobile app or Internet
Find a CO-OP Shared Branch or surcharge-free ATM right now at www.allco-op.org or call 1-888-SITE-CO-OP.*
*There are no surcharge fees at ATMs that we own and at ATMs that display the CO‑OP logo. Per our Common Features (Fee Schedule) there is a $1.25 fee per ATM withdrawal/transfer at ATMs we do not own and a $.50 fee per Account Balance Inquiry.
Xtend Shared Branch Locator

At over 250 Xtend Shared Branches nationwide, you can get convenient access to your Credit Union accounts and make transactions.
- Withdrawals
- Deposits
- Loan payments
- Transfers
- Balance inquiries
For a complete list of locations and hours, visit search.xtendcu.com.
Download the Xtend Shared Branch App from the App Store and on Google Play.