Is there tent camping there?

Yes, but check out the park in lyons colorado. St Vrain is good if you are fishing, Lyons is good if you are going for quite seclusion and nature.

Tent camping, yes

Yep

Yes

Tent camping is allowed, but there are no designated "tent sites", so an electric site is the cheapest option

yes there is, it is a dirt gravel pad there are some areas for grass but those are very limited. They're also concrete pads.