Mount St. Helens/Blue Lake Area

[hoosierf]

Can anyone recommend a campground in the Blue Lake area? I'm not too concerned with the facilities, but it would be best if kids could ride around the general area of the campground as I'm taking my whole posse. I've never camped in the area, but I do have a map for reference.

I want to head up this Saturday, but I don't have a reservation. Do you think I can get a site????

Thanks in advance for any advice.