If flying into eg Salzburg and looking to get to Uttendorf by train, then take a look at the web site www.oebb.at for train times to Zell am See. From Zell am See you can either get to Chalet Anna by taxi ( approx 35€ for an 8 seater), taxis available from outside Zell station, or catch the local narrow gauge railway train which leaves Zell am See from Platform 11 on the hour till 8pm at night and goes all the way to Krimml stopping at Uttendorf. This train is free in the winter with your lift pass, although a small charge is made between Uttendorf and Niedernsill. This train accesses all the main ski areas. There is a bus service, the 670 to Krimml which leaves the train station in Zell just after half past the hour and comes to Uttendorf. This is not free with a lift pass, costs around 4.80€ per person.
If you are planning to drive over, winter or summer, this gives you alot of flexibilty. In winter don't forget that you need soft compound (winter) tyres by law. The roads are clear and you will be amazed how easy it is to travel even in winter.
Car hire is around 200€ a week, I suggest from the airport rather than locally.
When you make an enquiry, I will send you information on car hire, driving in Austria, tips and help etc.
Different carriers fly into Salzburg, including Ryanair, Easyjet, BA