Berms

I am having two 2ft high berms formed in my front yard. What is the best soil mixture so that the berms stay firm and don't wash away? Any suggestions. Aside from obviously compacting the soil, is there a way to reduce erosion? Thanks.

I use raised beds with stones. Also you could use compost in the soil to prevent erosion. IE pine needles, fir cones, small rocks, etc. Terracing works well also.

I put large stones in the berm as will it slowes run off down,and makes a micro climate of sorts you can push a zone useing this.