These are obviously fossils (from Tooele County Ut) but what on Earth are they and how were these formed? My best guess, worm tubes of some kind. I'm an environmental scientist (not a paleontologist or geologist) so making a positive ID is challenging. I've collected rocks & minerals for years and along with whats in my yard I've been trying to post the ones I've collected over the years that have fossilized characteristics. These ones certainly fit the bill and I seem to have 6-7 of these rocks. These also have florescent elements when I place them under UV light, with florescent blues, greens, orange and even some yellows. The rocks are covered in florescent lichens & cliches. The soil where I live is rich in colorful cliche deposits and lichen cover many of the rocks since I live near the benches of Tooele around 5,350 feet.