What kind of caterpillars?

Observation by Maya Brubaker:

We saw this all over Moab. It’s a giant nest of caterpillars. I didn’t even know they did that! Do you know what kind of species this is?

LEO says:

We found a news article from local paper, The Times Independent, about an outbreak of tent caterpillars last year in early May as well as 20 years before. See Tent Caterpillar Infestation Returns to Castle Valley. See also the fact sheet from the Utah State University Extension Service on the Western Tent Caterpillar. These caterpillars feed on plants within their tent. They particularly like: "quaking aspen, alder, bitterbrush, California lilac, chokecherry, cottonwood, crabapple, fruit trees, mountain mahogany, nine-bark, oak, poplar, serviceberry, sumac, wild currant and wild rose."