NOT good!!

I hadn't known they were in Colorado. But yup.

At the link is some good info, but it looks like there isn't much of the way in organic treatments.

Here is a link that might be useful: link to CSU extension site

I had a terrible problem last year as my Virginia Creeper vines had hundreds of them and the lawn was suffering from the grub damage. Sprayed the hedge pretty heavy and soaked the grass with milky spore solution. Saw a few this year but nothing like last year. They were even chomping on the water hyacinth that I had in my pond filters. But within the garden I didn't notice any obvious damage.

Oh, no!
I hate Japanese beetles!