Service at the Canadian Port of Entry at Gretna has resumed now that spring flood waters have receded. 
Overland flooding from the Pembina River forced a number of highway closures in the area earlier this spring, including Highway 18 leading up to the port on the American side. 
In a news release, the CBSA said it recognizes border disruptions affect both travellers and industry, and would like to thank travellers and commercial partners for their patience.
You can follow the border wait times for ports of entry here.

Meantime, the U.S. Port of Entry at Neche, North Dakota is open daily from 8 a.m. - 4 p.m.