Finding this picture was rather easy, finding additional information on German ski units was rather complicated, therefore I think it’s better to copy and paste what I’ve found (with the indication of the source, of course).
“[…] there came into existence in December 1914 the Bavarian Ski Battalion 1 and the Württemberg Ski Company. In the second half of the winter, preparations were made to set up three further ski battalions, so that in May 1915, when the Alpine Corps began to be formed, there were already four of them. These four battalions were now brought together as Jäger Regiment 3. Out of this and Jäger Regiment 2, the 2nd Jäger Brigade of the Alpine Corps was formed.
The Württemberg Ski Company that had remained behind on the vosges front, was first, on 31 March 1915, renamed as the Württemberg Mountain Company. On 1 January 1915, it was enlarged into the Württemberg Mountain Battalion with 6 companies. It remained as such on the Vosges front as late as October 1916, then took part in the fighting in the Rumanian mountains. It was to be used later like any other infantry battalion, especially after it had been changed, on 3 May 1918, into the Württemberg Mountain Regiment on the Western front”.
Source: Hermann Cron,Imperial German Army, 1914-18: Organisation, Structure, Orders of Battle, 2006.
Their white uniforms look very modern, note the way the ski poles are used for firing!