South Dakota Immigration: State Rules vs. Federal Law - and What to Do Here

This article reflects South Dakota law and enforcement conditions as of June 2026. South Dakota has enacted a sanctuary ban and deployed one of the most comprehensive state-level enforcement programs of any non-border state. Key facts: Senate Bill 7 (signed by Gov. Larry Rhoden February 7, 2025; effective July 1, 2025) bans sanctuary policies statewide for all state and local government entities, including higher education institutions. Operation Prairie Thunder, announced July 28, 2025, deployed state troopers, National Guard administrative personnel, and corrections officers in coordination with ICE, initially targeting the Sioux Falls metro area and later expanding statewide. 287(g) agreements in effect as of late 2025: South Dakota Highway Patrol (Task Force, signed May 22, 2025); South Dakota Division of Criminal Investigation (Task Force, signed June 11, 2025); South Dakota Department of Corrections (Jail Enforcement Model, signed July 25, 2025; Warrant Service Officer, signed August 28, 2025); Minnehaha County Sheriff's Office in Sioux Falls (Warrant Service Officer, signed March 17, 2025); Hughes County Sheriff's Office in Pierre (Warrant Service Officer, signed March 7, 2025). National Guard: six members were activated in August 2025 to assist ICE with administrative processing and paperwork - three in Sioux Falls, three in Rapid City. Notable enforcement operations: Manitou Equipment and Global Polymer Industries, Madison (May 2025, 8 arrested); Trail King Industries manufacturing plant, Mitchell (ICE investigation confirmed July 2025); Drumgoon Dairy, Lake Norden (Homeland Security audit October 2025, 38 employees terminated due to citizenship documentation issues - this was an audit, not an arrest operation). ICE arrests in South Dakota from inauguration through October 2025 totaled at least 262. Most were male Hispanic individuals, primarily from Mexico and Honduras, per Deportation Data Project FOIA data analyzed by South Dakota News Watch. Operation Prairie Thunder was confirmed to continue into 2026. Verify current enforcement conditions at the ACLU of South Dakota (aclusd.org) or South Dakota News Watch (sdnewswatch.org).

Where South Dakota Stands

South Dakota is one of the most comprehensively enforcement-aligned states in this series for a state far from the southern border. It enacted a sanctuary ban in early 2025, stood up a governor-directed multi-agency enforcement operation within months, signed 287(g) agreements at the state agency level across Highway Patrol, Criminal Investigation, and Corrections, activated National Guard administrative support for ICE, and saw enforcement operations in small agricultural and manufacturing communities that are rarely the subject of federal immigration action.

The state's distinctive context is the personal connection between South Dakota's enforcement posture and the Trump administration: former South Dakota Gov. Kristi Noem became Secretary of Homeland Security and oversees ICE. Gov. Rhoden has publicly framed South Dakota's enforcement participation as direct support for federal priorities, and Operation Prairie Thunder was launched in explicit partnership with the Minneapolis ICE Field Office. The state's seven resident ICE agents had made 262 arrests since the inauguration through late July 2025 when Operation Prairie Thunder launched.

South Dakota's undocumented immigrant population is small relative to most states in this series - the state's total population is less than 1 million - but its immigrant communities are concentrated in Sioux Falls (the state's largest city and most diverse school district), in agricultural communities in the eastern part of the state, and in the Black Hills tourism economy. The Latino Festival and Parade in Sioux Falls was canceled in 2025 due to community safety concerns, according to the South Dakota Hispanic Chamber of Commerce, illustrating the climate change the enforcement surge has created.

Part 1: What Federal Immigration Law Actually Says

Immigration enforcement is exclusively a federal function under the Immigration and Nationality Act (INA). The federal government controls who may enter, remain in, and be removed from the United States. State and local governments cannot create their own immigration enforcement systems that conflict with the INA.

The Tenth Amendment anti-commandeering doctrine, established in Printz v. United States (1997), means the federal government cannot compel state and local agencies to enforce federal immigration law. South Dakota's approach, like other enforcement-aligned states in this series, works within this principle by directing its own subdivisions to cooperate - the state exercising authority over its own agencies rather than being compelled by the federal government.

Section 287(g) of the INA creates the voluntary delegation mechanism through which local agencies take on immigration enforcement functions. South Dakota's agreements cover three types: the Task Force Model (Highway Patrol and Division of Criminal Investigation), which authorizes trained officers to conduct immigration enforcement during routine patrol activity including traffic stops; the Jail Enforcement Model (Department of Corrections), which allows identification and processing of individuals already in state custody; and the Warrant Service Officer model (DOC, Minnehaha County, Hughes County), which allows execution of ICE warrants on individuals in local custody. The Task Force agreements held by Highway Patrol and DCI are the broadest in scope.

ICE detainers, Form I-247, are administrative requests, not court orders. South Dakota has no state law specifically mandating detainer compliance, but SB 7's sanctuary ban prohibits policies that limit cooperation with ICE, creating financial and legal pressure on local agencies to honor detainers.

Arizona v. United States (2012) is the controlling preemption precedent. South Dakota's enforcement framework - directing its own agencies to cooperate under federally authorized 287(g) agreements - operates within the constitutional space that case defined.

Part 2: South Dakota State Law

Senate Bill 7 - Sanctuary Ban (Signed February 7, 2025; Effective July 1, 2025)

Senate Bill 7 was the first bill signed into law in South Dakota's 2025 legislative session. Gov. Rhoden signed it on February 7, 2025; it passed the Senate 35-0 and the House 62-6. The law took effect July 1, 2025.

SB 7 prohibits any state agency, county, municipality, school district, or higher education institution from adopting sanctuary policies - defined as policies that limit cooperation with federal immigration enforcement. The law also provides legal protections for law enforcement officers carrying out immigration enforcement actions in the course of their duties. Gov. Rhoden described signing the bill as 'an important step in keeping South Dakota strong, safe, and free,' and framed it as support for federal priorities under the Trump administration.

With SB 7 in effect, no South Dakota city, county, or institution can formally adopt a policy limiting cooperation with ICE. There are no sanctuary jurisdictions in South Dakota and no protective local ordinances of the kind seen in Pennsylvania, Ohio, or Oregon.

Operation Prairie Thunder - Launched July 28, 2025; Continuing Into 2026

Gov. Rhoden announced Operation Prairie Thunder on July 28, 2025, at the Sioux Falls Public Safety Administration Building alongside Sam Olson, the Minneapolis field office director for ICE. The program was described as 'a comprehensive, targeted public safety initiative to protect South Dakotans' targeting gangs, drug crimes, and individuals in the country without legal authorization.

The components of Operation Prairie Thunder: the South Dakota Highway Patrol conducts saturation patrols - initially two per month in the Sioux Falls area and surrounding region, later expanded to communities including Belle Fourche, Huron, and Yankton - with state helicopters and aircraft for aerial drug enforcement and traffic enforcement; the Department of Corrections' parole absconder apprehension unit targets parolees who have stopped checking in; corrections officers flag inmates for parole to ICE custody where applicable; and corrections officers provide transportation of ICE detainees to and from the Minneapolis ICE regional headquarters; six National Guard members process ICE paperwork administratively in Sioux Falls and Rapid City, freeing federal agents for field operations.

The Highway Patrol statement on the 287(g) element of the program noted: 'It is important to note that any ICE contacts are incidental contacts - we aren't seeking out illegal aliens during the saturation patrols. However, the 287(g) agreement allows us to coordinate swiftly with ICE if a stop uncovers undocumented individuals.' The program originally ran from July 28 through December 2025; the governor's office confirmed in December 2025 that it would continue into 2026.

A Belle Fourche, Huron, and Yankton joint operation conducted through Operation Prairie Thunder resulted in 75 individuals taken into custody, 42 on drug charges, with 27 identified as ICE contacts. The operation illustrated how the program combined drug enforcement with immigration enforcement, with ICE contacts being a secondary output of criminal saturation patrols rather than a primary enforcement goal - at least as described by the state.

287(g) Agreements - Full State Agency Coverage

South Dakota's 287(g) agreements give the state one of the most comprehensive state agency enforcement frameworks in the country, particularly notable for a state far from the southern border. The agreements span three different model types covering different enforcement contexts:

Task Force Model - South Dakota Highway Patrol (signed May 22, 2025) and South Dakota Division of Criminal Investigation (signed June 11, 2025). These are the broadest agreements: trained officers can conduct immigration enforcement during routine patrol activity, including traffic stops on state highways. Any encounter with a South Dakota state trooper or DCI agent is a potential immigration enforcement encounter for anyone the officer has reason to believe may be in violation of immigration law.

Jail Enforcement Model - South Dakota Department of Corrections (signed July 25, 2025). Trained corrections officers can identify and process individuals already in state prison custody for potential immigration proceedings. The state flagged at least 10 inmates for possible parole to ICE custody at the time of Operation Prairie Thunder's launch, primarily nonviolent offenders near the end of their sentences.

Warrant Service Officer - DOC (signed August 28, 2025), Minnehaha County Sheriff's Office in Sioux Falls (signed March 17, 2025), Hughes County Sheriff's Office in Pierre (signed March 7, 2025). Trained officers can execute ICE administrative warrants on individuals in their custody.

National Guard Administrative Support

South Dakota activated six National Guard members in August 2025 to assist ICE with processing and administrative paperwork related to immigration enforcement. Three were assigned to Sioux Falls, three to Rapid City. The Guard members' role was administrative - processing arrest documentation, helping with paperwork - rather than making arrests themselves. Gov. Rhoden framed this as allowing ICE agents to stay in the field longer rather than returning to offices for paperwork.

Workplace and Agricultural Enforcement

South Dakota's enforcement operations extended into agricultural and manufacturing communities in the eastern part of the state. In May 2025, eight people were arrested on immigration charges at Manitou Equipment and Global Polymer Industries in Madison. In July 2025, ICE confirmed it was conducting an active investigation at Trail King Industries Inc., a manufacturing plant in Mitchell. In October 2025, Drumgoon Dairy near Lake Norden confirmed it was subjected to an immigration audit - different from an arrest operation - by Homeland Security; the audit resulted in the termination of 38 employees whose citizenship documentation was found to be outdated, inaccurate, or incomplete. These operations reflect the scope of federal enforcement in South Dakota beyond the Sioux Falls urban area.

Part 3: How State and Federal Law Interact in South Dakota

South Dakota's enforcement framework is one of the most tightly integrated state-federal cooperation systems in this series. The state has not merely facilitated voluntary local cooperation; it has engaged state-level agencies - Highway Patrol, DCI, DOC - in 287(g) agreements and deployed state resources including National Guard personnel directly in support of federal enforcement. This goes beyond the voluntary county-level cooperation that characterizes most states.

SB 7 closes the door on any local opt-out. No city, county, or institution in South Dakota can adopt a policy limiting ICE cooperation. Combined with statewide Highway Patrol and DCI Task Force authority, the result is that immigration enforcement can potentially occur in any law enforcement encounter anywhere in the state.

The Tenth Amendment framework is satisfied because the state has voluntarily chosen this level of cooperation - the federal government has not compelled it. South Dakota's Republican governor and legislature aligned with federal priorities and used the 287(g) mechanism to formalize that alignment. A future governor or legislature could undo these agreements, though SB 7's sanctuary ban would need to be repealed before any locality could formally limit cooperation.

Federal enforcement in South Dakota operates through the Minneapolis Field Office of ICE. The state's geographic position - Sioux Falls is equidistant from Minneapolis and Omaha - makes it a functional extension of Upper Midwest federal enforcement operations.

Part 4: What This Means for Families on the Ground

For immigrant families in South Dakota, the enforcement risk is comprehensive and statewide in a way that distinguishes this state from most others in this series. Highway Patrol troopers have Task Force authority on every state road. DCI investigators have Task Force authority. DOC has Jail Enforcement and Warrant Service authority. Hughes County and Minnehaha County sheriffs have Warrant Service authority. Operation Prairie Thunder extends active saturation patrols across multiple cities.

Sioux Falls is the state's largest city and the center of the most intensive enforcement activity. The Sioux Falls school district has worked to reassure students and families, and advocates have tried to provide information about rights, but the SB 7 sanctuary ban means the city government cannot formally adopt protective policies.

Agricultural and manufacturing communities in eastern South Dakota - Madison, Mitchell, Lake Norden, and the surrounding dairy and food processing belt - face workplace enforcement risk through both direct arrest operations and audit-driven employment terminations. The Drumgoon Dairy audit resulting in 38 terminations illustrates that enforcement consequences extend beyond criminal arrests to employment loss through document audits.

South Dakota has no long-term ICE detention facility. Individuals detained in South Dakota are transported by state corrections officers to the Minneapolis ICE regional headquarters or to detention facilities in the upper Midwest and beyond. Locating detained family members and accessing legal counsel must happen quickly, before transfer occurs.

The South Dakota Hispanic Chamber of Commerce cancellation of the Sioux Falls Latino Festival and Parade in 2025 due to safety concerns illustrates the community impact of the enforcement environment on daily civic and economic life. Workers in industries with significant immigrant labor - agriculture, dairy, food processing, construction, meat packing - face elevated enforcement risk.

Part 5: What You Can Actually Do

If Stopped by South Dakota Highway Patrol or DCI

South Dakota Highway Patrol troopers and DCI agents hold Task Force 287(g) agreements and can make immigration inquiries during routine traffic stops. Provide your driver's license, registration, and proof of insurance when stopped. You have the right to remain silent on immigration matters. Say: 'I am exercising my right to remain silent on immigration matters.' Do not answer questions about your birthplace, citizenship, or how you entered the country.

Do not physically resist. If you are being detained beyond a routine traffic stop, ask: 'Am I being detained or am I free to go?' If detained, request a lawyer immediately.

If ICE Comes to Your Home

Do not open the door. ICE cannot legally enter a home without a judicial warrant signed by a judge. An administrative warrant, Form I-200 or I-205, is signed by an immigration officer, not a judge, and does not authorize home entry. Ask through the closed door: 'Is this warrant signed by a judge?' If not, say clearly that you do not consent to entry.

You have the right to remain silent. Say: 'I am exercising my right to remain silent. I want to speak with a lawyer.' Do not sign anything without speaking with an attorney.

If Your Employer Receives an I-9 or E-Verify Audit

Employers in South Dakota may receive audit notices from Homeland Security Investigations requiring review of I-9 employment eligibility documentation. An audit is different from an arrest operation. If your employer is audited, you may be contacted about your documentation. Workers have the right to consult with an attorney before responding to employer requests for additional documentation. Contact legal services immediately if you receive notice that your employment documentation is under review.

If a Family Member Is Detained

Use the ICE Online Detainee Locator at locator.ice.gov immediately. People detained in South Dakota are transported by state corrections officers to the Minneapolis ICE regional headquarters or to detention facilities in Minnesota and beyond. Act immediately - transfers can happen quickly. You will need the person's country of birth and their full name and date of birth or A-Number.

Call the ICE Detention Reporting and Information Line: 1-888-351-4024.

Call the EOIR Immigration Court Information Line: 1-800-898-7180.

Contact the ACLU of South Dakota: aclusd.org. The ACLU-SD has provided Know Your Rights resources and tracks 287(g) agreements in South Dakota.

Contact Dakota Rural Action: dakotarural.org. Dakota Rural Action is a statewide advocacy organization that has supported immigrant communities in South Dakota.

Contact South Dakota Legal Services: sdlegalservices.org. South Dakota Legal Services provides free civil legal aid for qualifying low-income individuals including immigration matters.

Know the Risk Points in South Dakota

Every state highway patrol stop is a potential immigration enforcement encounter. Highway Patrol holds a Task Force 287(g) agreement and state troopers are authorized to make immigration inquiries and arrests during routine patrol.

DCI investigators hold Task Force authority statewide.

Any jail booking in Minnehaha County (Sioux Falls) or Hughes County (Pierre) involves agencies with Warrant Service Officer authority.

Agricultural and manufacturing workplaces have been enforcement targets statewide. I-9 audits can result in employment termination without arrest.

Operation Prairie Thunder saturation patrols are active in Sioux Falls and have expanded to communities across the state. Verify current operational status.

South Dakota has no long-term ICE detention facility. Transfers to Minneapolis or other states happen quickly. Contact a lawyer within hours of any detention.

Part 6: Legal Resources in South Dakota

ACLU of South Dakota: aclusd.org. Tracks 287(g) agreements and enforcement activity; Know Your Rights resources specific to South Dakota.

South Dakota Legal Services: sdlegalservices.org. Free civil legal aid for qualifying low-income South Dakotans including immigration matters.

Dakota Rural Action: dakotarural.org. Statewide advocacy organization supporting immigrant communities.

South Dakota News Watch: sdnewswatch.org. Comprehensive investigative reporting on Operation Prairie Thunder, workplace enforcement, and enforcement operations statewide.

Immigration Advocates Network: immigrationadvocates.org.

EOIR Immigration Court Information Line: 1-800-898-7180.

ICE Detainee Locator: locator.ice.gov.

ICE Detention Reporting and Information Line: 1-888-351-4024.

Summary

South Dakota enacted Senate Bill 7 (signed February 7, 2025; effective July 1, 2025), banning sanctuary policies statewide for all government entities. Governor Rhoden launched Operation Prairie Thunder on July 28, 2025, deploying Highway Patrol saturation patrols, National Guard administrative personnel, and corrections officers in direct coordination with ICE across the state, with the program confirmed to continue into 2026. 287(g) agreements cover the South Dakota Highway Patrol (Task Force), Division of Criminal Investigation (Task Force), Department of Corrections (Jail Enforcement and Warrant Service Officer), Minnehaha County Sheriff's Office, and Hughes County Sheriff's Office.

Notable enforcement operations included the Manitou Equipment and Global Polymer Industries arrests in Madison (May 2025, 8 arrested), the Trail King Industries investigation in Mitchell (July 2025), and the Drumgoon Dairy audit in Lake Norden (October 2025, 38 employees terminated). South Dakota has no long-term ICE detention facility; detainees are transported to Minneapolis and beyond. For families in South Dakota, enforcement risk is statewide and comprehensive: Highway Patrol and DCI have Task Force authority on all state roads, Operation Prairie Thunder saturation patrols are active, and the sanctuary ban prevents any city from adopting protective policies. Know your rights at every encounter, have a family emergency plan, and contact South Dakota Legal Services or the ACLU of South Dakota immediately if a family member is detained.

Sources and verification: South Dakota SB 7 (signed February 7, 2025; effective July 1, 2025; passed Senate 35-0, House 62-6); Gov. Rhoden press release, 'Gov. Rhoden Signs Ban on Sanctuary Cities' (news.sd.gov, February 7, 2025); DRGNews, 'Ban on Sanctuary Cities Takes Effect in South Dakota July 1, 2025,' June 26, 2025; South Dakota Searchlight, 'Operation Prairie Thunder Will Assist with Deportations and Boost Sioux Falls Law Enforcement,' July 28, 2025 (program announcement; Highway Patrol, DCI agreements; National Guard 6 members activated; Gov. Rhoden quotes; House Minority Leader Healy statement); South Dakota Searchlight, 'South Dakota National Guard Troops Begin Processing Immigration Paperwork for ICE,' August 18, 2025; South Dakota News Watch, 'ICE in SD - From Small Towns to Operation Prairie Thunder,' December 22-26, 2025 (287(g) agreement dates: Highway Patrol Task Force May 22, DCI Task Force June 11, DOC JEM July 25, Minnehaha County WSO March 17, Hughes County WSO March 7, DOC WSO August 28; Manitou Equipment/Global Polymer Madison May 2025 8 arrested; Trail King Mitchell July 2025 investigation; Drumgoon Dairy Lake Norden October 2025 audit 38 terminated; Belle Fourche/Huron/Yankton operation 75 taken into custody 42 drug charges 27 ICE contacts; 262 ICE arrests through late July 2025; Deportation Data Project FOIA data; Latino Festival cancellation; South Dakota Hispanic Chamber of Commerce quote); Aberdeen Insider, 'ICE's Year in South Dakota From Small Towns to Operation Prairie Thunder,' December 26, 2025 (Highway Patrol statement on incidental contacts); ACLU of South Dakota, 'What Are 287(g) Agreements,' May 21, 2025 (aclusd.org; Hughes County March 7, Minnehaha County March 17 agreements); NewsNation, 'Operation Prairie Thunder To Aid ICE,' July 29-30, 2025 (helicopters; Lakota aircraft; parole absconder unit; corrections transportation; DOC interest in 287(g)); Arizona v. United States, 567 U.S. 387 (2012); Printz v. United States, 521 U.S. 898 (1997). Volatile items requiring verification: Operation Prairie Thunder current operational status (confirmed to continue into 2026; verify at news.sd.gov); any new 287(g) agreements beyond those listed; current detention transfer destinations (Minneapolis field office; verify at ice.gov). Last verified: June 2026.