It looks pretty steep to me as it is. I would guess at least 50-60 degrees.  Maybe one just needs to use a little imagination.  Otherwise, you need to move/zoom wider where you can show more perspective to other parts of the landscape.  In this scene if you depicted someone climbing up above, I think it would be easier to visualize the angles involved.  We've all seen the shots of climbers either directly overhead or below, or clinging to a sheer cliff as shot from a distance.

I can swear there ain't no heaven but I pray there ain't no hell. _ Blood Sweat & Tears