I've ridden by Chaco Canyon several times now. You're never too tired to do a little exploring. The turnoff is about half way between Bloomington and Cuba NM - a 100 mile stretch of absolutely nothing. After about 10 miles of paved and 20 miles of unpaved roads, a natural landmark is visible in the distance. This is the last 5 or 10 miles of dirt road leading into Chaco Canyon.