We are looking at an RV (rental) trip around the 4 Corners and would like to visit Chaco Canyon. We are painfully aware of the challenging road conditions for the last 20-30 miles into Chaco. Anybody have experience in driving an RV to Chaco? Are there rental agencies that will allow one to take one of their vehicles into Chaco Canyon? Also what seems to be the best time of year to drive an RV when there is the least chance of rain and bad roads?