Facility county-jail Operational

St. Clair County Jail — Port Huron MI (County IGSA)

St. Clair, MI FIPS 26147
unknown
Bed capacity
Operator: St. Clair County Sheriff Mat King

Overview

The St. Clair County Jail in Port Huron, Michigan holds ICE detainees under an Intergovernmental Service Agreement (IGSA). The facility is managed by Sheriff Mat King and overseen by ICE’s Detroit ERO Office. It detains adult men and undocumented migrants on an administrative basis.

Port Huron sits on the Canadian border at the Blue Water Bridge crossing to Sarnia, Ontario, making the jail strategically significant for border-area enforcement.

Key Details

  • Address: 1170 Michigan Road, Port Huron, MI 48060
  • Operator: St. Clair County Sheriff’s Office (Sheriff Mat King)
  • IGSA: Active (in use as of 2025)
  • ICE oversight: Detroit ERO Office
  • Detainee types: Adult men, immigration detainees (administrative)
  • No 287(g): St. Clair County is NOT among the Michigan counties that have signed 287(g) agreements

Context

St. Clair County is one of four Michigan county jails holding ICE detainees (along with Calhoun, Chippewa, and Monroe). The border location is notable — illegal immigration from Windsor/Sarnia through the Blue Water Bridge crossing has been referenced in immigration enforcement discussions.

Despite the IGSA, St. Clair County has not signed a 287(g) agreement. Seven Michigan agencies have signed 287(g) MOAs (Jackson, Berrien, Calhoun, Crawford, Roscommon, Genesee, Taylor), but St. Clair is not among them. The heatmap’s 287g-agreement signals may reflect legislative pressure (Michigan House Resolution 128 encourages all sheriffs to sign 287(g)) rather than actual participation.

Heatmap Signals

Score 57 with 4 signal types: igsa (2), 287g-agreement (2), county-fight (1), facility (2).

Sources

Edit Report issue County profile
Last updated: Apr 12, 2026