As previously posted, most American whiskey distilleries are in the process of increasing their production capacity, for the first time since the 1960s.
Because many of the distilleries that closed in the last several decades had usable warehouses, the remaining distilleries haven't had to increase warehouse capacity until recently. For all intents and purposes, every good warehouse in Kentucky and Tennessee is now full. They have to build new ones.
Here is an example of a pretty typical new warehouse. This one is at the Jim Beam Booker Noe plant (Boston, Kentucky). The new ones at Wild Turkey look very similar.
It is a rack house. A few years ago, Beam experimented with palletized warehouses, which were big, open, aircraft hanger-type buildings with barrels stacked, on end, on pallets, so they could be moved around with fork lifts. Beam still has some of these but isn't building new ones. All things considered, they found that the traditional rack house works better, at least for them.