The public might notice an Army Black Hawk helicopter flying around Oak Harbor Thursday.

Local agencies on Whidbey Island are participating this week in a multi-state drill called Cascadia Rising.

It’s a region-wide exercise to test the emergency response to a major disaster in the Cascadia Subduction Zone.

Most of the preparation will happen behind closed doors but the helicopter landing behind the city’s municipal shop on the north end of town might be the visible part of the drill locally, said Eric Brooks, who heads Island County Department of Emergency Management.