3 sided horse "run in"

I want to build a 3 sided horse "run-in" for my pasture horses. I've seen them built out of tin and out of wood, but I can't find plans anywhere. Most of the ones I find are for permanent structures and I want one that is movable.
It just needs to...

be a place that my pasture horses can get out of the wind during the winter because I hate keeping them in the barn all winter.

Thank you!

Most anything that's moveable... and roofed, is going to blow over in winter wind. Tin is never a good idea, because of sharp edges, and rattly noise in the wind that scares horses.

If you want portable...you could buy a "mare motel" . Those are roofed, and made of portable bar panels... You could add plywood for more wind protection on the windy sides.

yeah, you can buy ready made things like dawndalyce said, probly your best option.
DO NOT USE TIN dangerous

All over Missouri we have tin run ins that are framed in wood so I'm not worried about the tin, it won't have sharp ends sticking out. Buying those pre-made buildings is very expensive, a 12'x24' run is about $2100.