Uneven ground and small gullies

I am looking for advice on fencing uneven, rocky ground and small seasonal streams/gullies. I was thinking of using hedge or ceder corner posts and stays, then mostly tpost through out the fence with corner posts at gates and where paddocks meet, and corner posts every 100 feet or so.
The issue is that there are a few spots with small gullies. They are maybe one and a half too three feet across and the same down in a triangle. Most of the gullies are very rocky (at first I had thought to dig a small trench to put the fence down into and a post at the bottom of the gully). There is also a spot with a small stream that runs year round that I would like to fence. So in both places the issues is basically the same, just one has water in it and the other areas do not. I need to keep in dogs, goats, chickens and ducks.
Some thought's I'v had: Fence from t-post to t-post with a post at the lowest point I can get, go across the gully to the other side and put in another t post. Fasten hardware cloth to the bottom of the fence and use masonry bolts into the rock to attach it to the rock. Or Build a small frame measuring out the shape of the gullies and using that for hardware cloth, then filling it in with rocks. I don't think filling it in with rocks would work for the stream because water surges with rain could move them. I would also want something larger than hardware cloth so small fish could pass through but animals could not.
Also, how on earth do you dig a post hole and/or drive a t post if you only have about a foot of soil before rock?
I'm sure there is a simple solution to this but I'm just not thinking of it!

Regarding fence posts in rocky areas ,  I have had success making liberal use of concrete.   In one place I have several wood posts in a row sunk into 20 gallon containers filled with concrete.  It worked well for goats.  It would be useless for cattle or pigs.

Rock jacks are an option where buried/driven posts don't work.


I have been dumping rocks along the low spots in fencelines as I rockpick, seems to be working well. Your dips are larger, so I think you are on the right track as far as needing something to retain the rocks, like gabion baskets.

For the stream, seems like a robust solution would be a concrete spillway with a steel grate sized to exclude/retain whatever animals the fence is meant for... short of that, big rocks or large gabion gaskets will be less prone to flood displacement than small ones, and rebar stakes could be a budget 'grate'..

D Nikolls wrote:Rock jacks are an option where buried/driven posts don't work.


I have been dumping rocks along the low spots in fencelines as I rockpick, seems to be working well. Your dips are larger, so I think you are on the right track as far as needing something to retain the rocks, like gabion baskets.

For the stream, seems like a robust solution would be a concrete spillway with a steel grate sized to exclude/retain whatever animals the fence is meant for... short of that, big rocks or large gabion gaskets will be less prone to flood displacement than small ones, and rebar stakes could be a budget 'grate'..

I'm really liking the idea of rock jacks and think it would be a good way to put up a temporary but permanent fence. That way I can invest in field fence and poles etc while still observing my land and deciding where to put the final fencing. Do you know how well they hold up to mini goats (Kinders) and big dogs (Pyr mix)?