They are harmless to the lawn and their removal won't do much to reduce their reappearance, though you can keep disposing of them if you wish. They are likely produced by a fungus growing inside decaying wood, probably from an old tree stump or subsurface roots left after tree removal, though some mushroom-bearing fungi subsist on other types of decaying organic matter in the soil. Moisture in the form of regular irrigation may be fueling their growth, but either way, when their food source is exhausted, they will stop coming back. Below is a little more information, but a word of caution in case you're curious - although some pages mention edibility, we firmly do not recommend consuming any mushroom that can't be positively identified.

https://hortnews.extension.iastate.edu/2005/10-5/puffball.html

https://hortnews.extension.iastate.edu/2018/08/hard-puffball

You can also contact the Colorado Mycological Society for a more positive identification.