migrating Sandhill Cranes

in September 2016 I heard Sandhill Cranes when we were up Mount Washington but could never see them -- this year on September 17th we were up at the Strathcona meadows again and with some cloud drifting around could hear Sandhill Cranes coming from the North-west -- in total at least 140 birds passed to the south-east in about 90 minutes -- superb hearing them calling but never low enough for decent images -- assumedly these are Alaskan breeders en route to California ? a few birds were flying with no legs! odd to see them tucked up like that