The French Alps are well connected to the rest of the country. There is an international airport close to Grenoble (GNB) and one in Chambery (CMF) and Lyon (LYS). Most cities have a direct TGV (fast train) connection with Paris. Many towns are also connected by ordinary trains. There are highways to many of the valleys.
You can also fly into the international airport of Geneva (GVA) in Switzerland. We can assist you with private transfers, if you would like to combine Grenoble with a visit of Geneva.