Great blue herons...

are beginning to flock to their rookery along the Colorado River near milepost 9 on Utah 128, between Moab and Castle Valley, Utah. Here's a wide shot of several of their nests in a Gamble oak grove on the opposite side of the river (click to enlarge):

And a close-up of one of the big ladies (Ardea herodias) standing in the apical nest:

I've counted as many as a dozen nests in this cluster, and most are usually occupied by late spring based on my prior observations.