1930 A. Lunn Compl. Ski-runner xi. 130 The chief argument used in favour of no-fall racing was the fact that such intentional sitzmarks occasionally paid. But the sitzmark is a useless manoeuvre against modern runners who have mastered the art of tail-wagging.

1935 Punch 13 Feb. 176/2 One seems to see as in an inspired flash..the insidious vileness of a sitzmark. [Note] Deliberately sitting down in the snow when no other method of stopping seems possible. Very degrading.

1973 P. A. Whitney Snowfire xvi. 306 I sat down and let my skis go out from under me, sliding a little way on the seat of my pants, leaving sitzmarks behind me.

1977 Globe & Mail (Toronto) 16 Nov. 37/6 My rump has had much practice from last winter's skiing—sitzmarks were almost second nature to it.

2004 A. G. Coleman Ski Style iv. 131 Roughly equivalent to divots on a golf course, these sitzmarks needed filling.

1935 Sierra Club Bull. Feb. 7 One should be ashamed to make a long descent by ‘sitzmarking’ at every turn.

1947 F. Smythe Again Switzerland ii. 22 To fall backwards and sitzmark is the hallmark of the craven.

1959 Ludington (Mich.) Daily News 24 Jan. 8/5 During the 1957-58 season, some 54,500 skiers slalomed, snowplowed or sitzmarked on hills, slopes and trails.

2016 K. N. Johnson in B. Paone et al. Journey of Words (e-book, accessed 23 Mar. 2018) Mr. Lundgren..might know who was sitzmarking up his track.