With some dread, we too checked in with Customs in Ely on our way out on the 25th ... and we too found it closed.

Sign somewhere said to call one of several other places. Guy in our party did that and we were finished within a couple of minutes. I think  they requested just names and birth dates.

-- kypaddler

(and I'm very positive that any terrorist who decided to infiltrate the United States by flying or boating into Canada, renting or building a canoe and paddling through Quetico and out into Ely ALSO checked in.)