There are different classes of e-bikes. Class 2 e-bikes can be ridden without pedaling. Other classes of e-bikes are pedal assist, meaning you need to pedal.
ETA: rules vary by location, but in Boulder City and County, class 2 e-bikes are allowed on streets, sidewalks, multi use paths, and some open space trails.
These vehicles could not be pedaled because they physically do not have pedals. Just footpegs.
Do Class 2 require the ability to pedal? Or is that not necessary for a bicycle?
Can I get my kid an electric dirt bike to ride to school on the lobo trail?
Class 1 and 2 e-bikes are allowed on the LoBo trail, except for a short stretch at Twin Lakes.
https://assets.bouldercounty.gov/wp-content/uploads/2019/12/e-bikes-map.pdf
I don’t know whether there is any enforcement in that section. I don’t recall seeing any County open space rangers on the LoBo trail, but I only ride the section east of Boulder a handful of times a year.
Reading more on the subject, I see that Colorado law requires class 1 and 2 e-bikes to have pedals. So, if someone wants to ride on a sidewalk, MUP, or open space trail, they need to have pedals. I don’t fully understand the concept, since a class 2 e-bike has a throttle. But, that appears to be the law.
As for an e-dirt bike, you’d need to research whether it qualifies as a class 1 or 2 e-bike. Those are well-defined terms, and a bike store should know the answer for a particular model. For example, class 1 and 2 e-bikes are capped at 750 watts. An e-MTB qualifies as an e-bike, assuming it is under 750 watts and stops providing power at 20mph.