There were multiple Juniors in the Cat 5, Cat 4, Cat 3-4, and P123 races yesterday at Bethel.

Age is separate from Category. Everyone has both.

So you can be under 18 but that doesn't stop you from being, say, a male or female. Or a Cat 5 or 4 or 3 or whatever.

A 10 year old placed very highly in a cross race we promoted last year, in the 4s (he might have gotten 8th, I'm not sure). I think he even made a video of his season.