Teen looking to learn cob building techniques

We're a homeschooling family in Spokane, WA looking for opportunities to learn in the NW. Our oldest two (14 and 11) are interested in natural building techniques (especially cob) and want to get their hands dirty. If you have a project that needs extra hands and it's within a half day's drive, I am more than happy to deliver some helpers. Ideally, a couple days in a row, or a monthly project day would be easiest to commit to, rather than a week or more at a time. Please let us know of any workshops or classes that might fit the bill as well.  Thank you!