Where are the scrutineers?

Here in Canada when there is a federal election, each party candidate is allowed to have a scrutineer at each polling station to watch the ballots being counted.

Doesn't the U.S. have a scrutineer for each candidate at each polling station?

I can understand voter fraud happening in many ways, but I can't understand how there isn't a scrutineer representing each candidate at each polling station and/or ballot counting area.

Can anyone explain?