back yard practice area

I have a section of back yard that is out of view of the house. It measures 115 feet by 35 feet, it's flat and open with only 1 tree in one corner. I was thinking about setting it up as a small low speed obstacle course. I will be riding a 250 by the way Maybe some logs and large rocks to practice balance and tecnique. Has anybody done this? Any suggestions? Thanks

No problem with mowing this section is completley hidden by huge shrubs and the wife hardly ever goes back there:p I like the idea of a few switchbacks, I suppose a series of berms could double as a whoop section. If I lay it ouy right I could have multiple lines through the same area making the most of a limited space. Heck I could add bleachers and call it Arenacross:D By the way I am close to my riding area to "5 minutes" but there are times when it would be nice to play around for an hour like we did when we were kids in the back yard.