South Dakota — Operation Prairie Thunder, 5 state 287(g)s, National Guard paperwork, ag audits
South Dakota has become a laboratory for state-federal immigration enforcement integration. Under Governor Larry Rhoden, the state launched “Operation Prairie Thunder” in July 2025, combining highway patrol saturation patrols, five 287(g) agreements, and National Guard administrative support for ICE. By October 2025, ICE had made 295 administrative arrests statewide; state troopers had “handed over” 71 people to ICE. The operation expanded into 2026 with patrols in Brookings, Hot Springs, Huron, and Yankton.
Operation Prairie Thunder
- Launched: July 28, 2025 by Governor Larry Rhoden
- Originally scheduled: July 28 - December 2025; expanded into 2026
- Structure: Joint SD Highway Patrol + ICE enforcement operation
- Statistics (as of late 2025):
- 71 individuals handed over to ICE by state troopers
- 295 ICE administrative arrests statewide (Jan 20 - Oct 15, 2025)
- 406 total individuals in custody from the operation
- 260 of 406 (64%) have drug charges — majority of activity is drug/traffic enforcement
- 12 saturation patrols completed by March 2026
- 2026 patrol locations: Brookings, Hot Springs, Huron, Yankton, Belle Fourche
- Profile of ICE arrestees: 98% male; majority Mexican and Honduran nationals
Sources:
- ICE and SD law enforcement expand Operation Prairie Thunder into 2026
- SD News Watch: ICE in SD — from small towns to Operation Prairie Thunder
- Operation Prairie Thunder wraps up 12th patrol in Hot Springs
- Operation Prairie Thunder concludes patrol in Brookings
Five 287(g) Agreements
South Dakota has five separate 287(g) agreements with ICE, a remarkably comprehensive state-level buy-in:
| Agency | Agreement Type | Date Signed |
|---|---|---|
| Hughes County Sheriff’s Office (Pierre) | Warrant Service Officer | March 7, 2025 |
| Minnehaha County Sheriff’s Office (Sioux Falls) | Warrant Service Officer | March 17, 2025 |
| SD Highway Patrol | Task Force Model | May 22, 2025 |
| SD Department of Criminal Investigations | Unknown | June 11, 2025 |
| SD Department of Corrections | Jail Enforcement Model | July 25-27, 2025 |
The Task Force Model (Highway Patrol) allows officers in the field to question and process suspected immigration violators. The Warrant Service Officer model allows jail staff to serve ICE warrants on people already in custody. The Jail Enforcement Model (DOC) allows corrections officers to identify and process potential immigration violators serving time in state prison.
Sources:
- AG Jackley and Minnehaha Sheriff Milstead detail 287(g) program
- SD Searchlight: AG clarifies scope of immigration enforcement agreements
- ACLU of South Dakota: What are 287(g) Agreements
National Guard Administrative Support
In August 2025, Governor Rhoden deployed 6 National Guard members (3 in Sioux Falls, 3 in Rapid City) to process ICE arrest paperwork. A Guard liaison serves as the communication point between ICE and the 6 processors. Purpose: free ICE agents to remain in the field rather than doing administrative work.
This is part of a broader GOP-state trend (Florida, Texas, Oklahoma also deploying Guard for immigration support).
Sources:
- SD Searchlight: South Dakota National Guard troops begin processing immigration paperwork for ICE
- CSMonitor: National Guard takes new role aiding immigration operations in GOP states
Detention Flow
South Dakota has no dedicated ICE detention facility. The detention flow is:
- ICE arrest (or state trooper handoff to ICE)
- Minnehaha County Jail (Sioux Falls) — primary holding, 72-hour max for non-criminal immigration holds
- Pennington County Jail (Rapid City) — secondary holding
- SD State Penitentiary (Sioux Falls) — for those already serving state sentences
- Transfer to ICE detention facility (likely Freeborn County MN, Sherburne County MN, or other Fort Snelling ERO field office facilities)
The Fort Snelling ERO field office (Minneapolis) manages South Dakota along with Minnesota, Iowa, Nebraska, and North Dakota — 26 jail arrangements total in the region.
Workplace/Community Enforcement
Drumgoon Dairy Audit (Lake Norden, Hamlin County)
- Date: May 2025 (audit); October 2025 (reporting)
- DHS conducted an I-9 audit at the 6,500-cow dairy
- 38 employees terminated for inaccurate/outdated/incomplete work authorization
- Workforce reduced from 50+ to 16 employees
- Farm located 5 miles from DHS Secretary Kristi Noem’s home
- Owners used EB-5 program to start the operation in 2006
Madison Manufacturing Raids (Lake County)
- Date: May 2025
- ICE arrested 8 people at Manitou Equipment and Global Polymer Industries in Madison, SD
- Part of a broader pattern: “dozens of immigrants detained in South Dakota”
Huron Deportation (Beadle County)
- Date: August 2025 (arrest); deported by early 2026
- ICE detained a Huron resident outside his home
- Deported to Guatemala; wife remained in South Dakota
- Reported by SD Searchlight in March 2026
Sources:
- SD Searchlight: Noem’s South Dakota neighbors hit with immigration audit
- DairyHerd: Overnight Exodus
- SD Searchlight: Men arrested in Madison among dozens detained
- SD Searchlight: Wife of deported Huron resident
Courthouse Arrest / Mistrial (June 2025)
ICE arrested a defense witness at the Minnehaha County Courthouse in Sioux Falls in June 2025, causing a mistrial in an aggravated assault case. The arrest occurred in front of the witness’s wife and infant daughter, and was observed by jurors on break. The Public Defender’s Office alleged this “directly undermined the defendant’s constitutional right to a fair trial.”
Sources:
- KELO: ICE arrest at Minnehaha County Courthouse
- Dakota News Now: State’s attorney details events of ICE arrest that caused a mistrial
Community Impact
- Hispanic residents report feeling less safe across the state
- Sioux Falls Latino Festival and Parade canceled in 2025 due to safety concerns
- Rapid City Mexican restaurant fought false rumors of being raided
- SD Voices for Peace providing know-your-rights resources
Heatmap-Relevant Counties
| County | FIPS | Score | Key Role |
|---|---|---|---|
| Roberts | 46109 | 56 | IGSA + 287(g) + budget-distress |
| Faulk | 46049 | 56 | IGSA + 287(g) + budget-distress |
| Lawrence | 46081 | 41 | IGSA + 287(g) |
| Meade | 46093 | 41 | IGSA + 287(g) |
| Brown | 46013 | 41 | IGSA + 287(g) |
| Minnehaha | 46099 | 34 | Primary ICE holding jail, 287(g) |
| Pennington | 46103 | 20 | Secondary ICE holding jail |
| Yankton | 46135 | 10 | IGSA, Operation Prairie Thunder patrol site |
Note: Roberts County (Sisseton, 100-bed jail) and Faulk County (115-bed jail) both score highest on the heatmap due to budget distress combined with IGSA and 287(g). These small, rural, budget-stressed counties with oversized jail capacity are classic candidates for expanding ICE detention contracts. No specific reporting found confirming active ICE detention use at these facilities — worth monitoring.
Key Questions for Follow-up
- Are Roberts County and Faulk County jails currently holding ICE detainees, or just on standby?
- What is the per-diem rate for ICE holds at Minnehaha County Jail?
- Where are SD ICE detainees being transferred for long-term detention? (Likely MN facilities)
- Is the state legislature considering any anti-sanctuary or immigration enforcement bills?
- What is the connection between Operation Prairie Thunder’s drug enforcement and immigration pipelines?