After a three-year break, the Rocky Mountain Air & Ground Festival (aka, the Rocky Mountain Air Show) is back today, Saturday August 4, 8 a.m. tp 4 p.m. — and grounds admission is FREE, though parking costs $5). Highlights are the air acrobatics with performances from 10 a.m. to noon and again from 1:30 to 3 p.m. Ongoing are ground attractions including food and merchandise vendors, many offering unusual air-themed items. Rocky Mountain Airport, 11755 Airport Way, Broomfield, 303-271-4850.