A foundation in insanity?

[avocadofarmer]

Howdy gents, first time poster here...

I've got a piece of property in Southern Ca thats fairly off the beaten path. It's got a sweet little creek running through it that never seems to go dry. Lots of nice oaks and sycamore trees and very private. I was looking around and thinking that it would be pretty cool if I could construct a yurt on the bank of the watershed (its quite large, no flooding concerns where I'm looking to erect the yurt) and enjoy the shade and sound and general ecosystem of the area.

The spot I like sits nicely in a group of large oaks and would be in a half shade/half sun setup which sounds pretty good to me. The issue with this site is the foundation. Unfortunately years ago someone was 'farming' here and the demise of that shoddy operation can be witnessed by the bulldozer path where they pushed a pile of cut avocado trees into the creek. The trees were pushed down a narrow ravine (10 ft wide or so) leading to the larger creek bed. They've been there for a good 10 years and are basically acting like a retaining wall.

My idea is to place some steel I beams across this little ravine, anchor them into the solid soil/rock that remains on either side, build a deck and erect a 25-30 ft dia yurt. The total distance spanned with the steel I beams would be around 35 ft at the widest point. From what I've seen most people choose to put their yurts on relatively flat or at least stable ground. If I had to put a concrete anchor in the middle of the ravine I imagine I'd have to dig 10-20 ft deep before I hit anything solid enough to use. To avoid this, I just thought of the I beam idea.

I've attached a few pictures, hopefully they can add to my words.

Any caveats or tips you guys might add?

Thanks!