As I recall, there was what was supposed to be a temporary Canadian Border restriction, something like 200 miles, in which no US stations were authorized. In some cases, stations were allowed with reduced power at Night if they were somewhat closer. The Canadian stations near the border were on 1610, 1630, 1650, 1670, and 1690. US stations near the border were supposed to be on 1620, 1640, 1660, 1680, and 1700. The moved 1690 to Berwyn from somewhere else further away. But there wasn't another open window for other stations as I recall.