1st off, I don't believe the reasons they give for age restrictions. "Competent enough to walk, able to learn snowboarding" is a saying some people have. I personally feel they are afraid the kid will not want to learn to ski which is far more efficient for covering various different terrains.
Kirkwood has been rated the best place to learn. If they won't do it, I will. Most of these resorts are on public property, don't let them lie to you and keep you from enjoying your resources.
SnowboardBetter.com 
