NCUA-insured credit union

Sentinel

Credit Union headquartered in Box Elder, South Dakota.
Source: NCUA call report data, data as of March 31, 2026, fetched September 5, 2026
Total assets
$197.02 million
Branches
8
NCUA-insured since
1971
Established
1955

Headquarters and contact

AddressPo Box 700
Box Elder, SD 57719
CountyMeade
Websitenot published in NCUA data
Phone(605) 923-1405

NCUA record

NCUA Charter10257
Federal Reserve RSSD ID727183
StatusActive
Charter type1 (NCUA)
Financials as ofMarch 31, 2026

Routing number

NCUA does not publish ABA routing numbers, and many credit unions use different routing numbers by state or by account type. The reliable places to find yours: the bottom left of a check from this credit union, the "account details" screen in its online banking, or its official website.
See how your odds compare before you apply at Sentinel.

Offices

Main main office
Ellsworth AFB, SD
2723 Lemay Blvd, 57706
(605) 923-1405
9 A.M - 5 P.M Mountain Time
Liberty Branch
Box Elder, SD
441 N Ellsworth Rd, 57719
(605) 923-1405
Lobby: M-F 9:00 AM-5:00 PM Drive Up: M-Thursday 8:00 AM-5:00 PM Drive Up: Friday 8:00 AM-5:30 PM Drive Up: Saturday 9:00 AM-12:00 PM
Radar Hill Branch
Box Elder, SD
22752 Mule Deer Trl, 57719
(605) 923-1405
Custer Office
Custer, SD
18 Mount Rushmore Rd, 57730
(605) 673-4416
Monday thru Thursday 9:00a.m.-5:00p.m.Friday 8:00a.m. to 5:30p.m.Saturday 9:00a.m. to 12:00p.m.
Hill City Office
Hill City, SD
553 E Main St, 57745
(605) 574-9596
Monday thru Friday 8:00a.m. to 5:00p.m.Saturday 9:00a.m. to 12:00p.m.
Triple Crown
Rapid City, SD
4011 Triple Crown Dr, 57701
(605) 923-1405
9 A.M - 5 P.M Mountain Time
Haines
Rapid City, SD
1430 Haines Ave Ste 101, 57701
(605) 923-1405
9 A.M - 5 P.M Mountain Time
Winner
Winner, SD
511 E 2Nd St, 57580
(605) 842-3581
8 A.M - 4 P.M. Central Time