I've always followed the same basic things for all my engines, 22r, hybrid 20/22, 3,4L, V8, etc...
1. No towing for 5000ish miles.
2. No high speeds, 55-60 should be ok
3. Vary the RPMs, don't take it easy, but don't be too rough. Give it some good revs occasionally.
4. Use good oil.
As for viscosity, I'm not sure what you guys typically use in CO, but 10W-30 or 20-50 should be ok, just don't want it to freeze up ..
There's my 
I have often wondered what the speed of a vehical has to do with engine break-in procedures. The engine break in is effected by two things outside of the the actual engine parts, (1) Engine RPM, and (2) Engine Load.
It makes sense to not overload the engine with towing, but actual speed (mph) has nothing to do with it.
As for being in Colorado, just make sure you are not breaking it in with cold starts!
