My dd is in Irish Step Dance - the teacher actually has a group in ID too - McNulty Irish Dancers.
When I first looked into it, a friend told me not to, it was too competative, you have to drive all over the country - its very expensive - so I didnt look any further!!
Then we happened into an Irish Store that had 4 or 5 dancers dressed and moving - so dd asked them, they gave us the website, and they had classes near our house. For the first year the classes are around $10 45 min session I believe... and you just wear shorts, tshirts and a ballet or jazz soft shoe to learn the basics.
Then once dd learned the jig and the reel ( it took about a year I want to say) dd decided to go to her first competition called a feis - we bought the hair (curly wig $50) soft shoes (like ballet, but they lace different) and rented the class skirt, and vest, and shirt ($40 a year rental) She won first place!!
So now she takes workshop $15 for a 3 hr session. and then she can move up to the next level dress (I think $100 rental) the fancy schmancy dresses can be rented for around $500 and you can buy your own for $1100!
She also takes a heavy shoe class - it is a mix of clogging, tap, the shoe is heavy, its not a metal tap but a wooden (sometimes fiberglass I've heard)
They really work hard - I was amazed. DD took ballet for a couple of years, but she loves this so much more -
I'd do a google search for Irish Dancers plus your town... Our teacher was saying that most do sign ups to do shows online, so its a good bet you'll find something!!