We went West on 14 from 287 out of Fort Collins and made the mistake of buying a campsite at Kelly Flats. Just down the road was 63e, where we found everything from flatbed semis to college buses to honda civics. However at a small branch about 4 miles up we found such a good "dispersed camping" site that we abandoned the pay site by the large river.
There were other great sites that we found while exploring:
And we tested out the Deavers and the Rancho 9000s.. not much up travel but I haven't found a big rock to test: