There are two main ways to access the area of El Chalten: Route Nacional (RN) # 3 that borders the Atlantic coast is the busiest (paved all the way) and RN No. 40 parallel to the Andes (mostly gravel).
The possibilities to arrive by bus are: from the town of El Calafate (215 km drive) south of the province of Santa Cruz or from Perito Moreno (220 km drive) north of the province of Santa Cruz. From and to El Calafate regular buses run from the month of October to May, and from Perito Moreno transportation service is not regular.
The nearest airport is the International Airport of El Calafate, and from there you have to continue by bus to El Chalten (215 km / 4 hours). From Buenos Aires there are daily flights to El Calafate (3 hrs. Direct flights).