How to make a long origami stairs

(page 3)

3rd picture of long origami stairs

03.

Mountain-fold in half vertically and then "unfold" .

Prepare to apply a horizontal "gate-fold" and then "unfold" .

4th picture of long origami stairs

04.

Apply the horizontal "gate-fold" of the step #3 and then "unfold" .

Prepare to apply a vertical "gate-fold" and then "unfold" .