The declaration starts a process by which state agencies can get additional funding, said Greg Wilz, director of the Homeland Security Division of the state Department of Emergency Services.
Dalrymple said in the declaration that the state is committed to protecting the right to lawful protests, but recent events have created a "significant public safety concern."
The protests have grown substantially over the past week as about 1,500 people have gathered to demonstrate against the pipeline being drilled under the Missouri River. Large campsites have been established for the protesters. Twenty-nine people have been arrested during the demonstrations.
