Where can I find split rail fencing suitable for horse pasture?

Most websites focus on plastic fencing. What I want is livestock-suitable post and rail fencing for paddocks.|||Any lumber yard has the stuff you need, you just have to know WHAT size posts, rails, etc you need. Get out there and measure it up and do the math. Then hit Lowes or Home Depot or whatever.|||Does Tractor Supply carry this? You might check local lumber merchants such as: Lowe%26#039;s, Home Depot and private lumberyards. Maybe go to a sawmill.