Heather Smith Thomas

Back to: Home
April 27, 2009
Follow Home

Fencing tips for rocky terrain

Fencing can be a difficult challenge in the rocks, especially when it's too rocky to dig post holes efficiently, or to set posts using a tractor-mounted driver (post pounder).

Michael Thomas, who ranches in Lemhi County near Salmon, ID, has been building fence all his life, and has also done custom fencing for other ranchers. In some situations the only options if you have to set a brace post in the rocks are to dig out the hole with a backhoe (in terrain where you can get the machine to the fence), or keep chipping away at the rock (if it's a type of rock formation that will chip and break) or prying them out with a hand bar if it's on a steep mountainside where you can't get to it with machinery; or in some instances, use a rotohammer electric drill that runs off a portable generator. These work well for drilling a small diameter hole into a solid rock ledge, to insert a steel post, or even to create a large enough hole for a wooden brace post, says Thomas.

In some types of terrain, however, where it's not too steep and there are a lot of surface rocks you can utilize an above-ground basket/cage full of rocks as a brace point to anchor your fence. You can gather and stack the rocks and then secure them with wire, or make a cage first and put the rocks into it.

"Net wire works fine to create the cage around the pile of rocks, to hold them in place," says Thomas. "The rocks are heavy enough that you only need to make a cage about three to four feet in diameter or width, to give you a solid anchor. You can secure your fence wire to the rock cage and stretch it from there."

This gives enough weight to hold any fence securely. If terrain is too rocky for setting wood posts, you can usually put steel posts into the ground far enough to hold, using the rock baskets every so often for braces.

Other strategies for rocks, if using a post pounder to set wood posts along a challenging fenceline, is to use a metal "post" to create a pilot hole. The metal post will often go down through rocky ground if it's not solid bedrock, pushing aside the rocks, or penetrating frozen ground, whereas a wood post would be forced out of line or just shatter. One of Thomas' neighbors made a seven foot tall metal pilot post to create holes for wood posts in difficult conditions, and several ranchers (including Thomas) have borrowed it on occasion when they have a tough fencing job.

"The post for making the pilot hole is like a regular wood post but is only about three or four inches in diameter and creates a hole to put the wood post into," Thomas says. "The pilot post is hard/solid enough that you can drive it into just about anything but solid rock. The pointed bottom part is solid steel about three feet long, and the rest of the post is hollow, like well casing."

This makes it a little lighter to carry around, but it's still very heavy.

"The top has a solid cap on it, for the post pounder to hit," he says. "You can drive that pilot post down as far as you can and then pull it out with the tractor loader, and insert your wood post into the pilot hole and drive it in - forcing it into the slightly smaller hole - and the post will be very solid and secure."

Other alternatives are a completely above ground fence such as a jackfence (buck fence) or worm fence. A worm fence is created by stacking logs or large diameter poles upon one another, interlocking in two directions. The finished fence is a continual series of corners/angles. This type of fence is safe for cattle but not for horses, since a horse may be injured if it gets crowded or chased into a corner by a herdmate.

A jack fence of poles works well where the ground is too rocky to set posts, but in windy country this type of fence must be anchored securely so it won't blow over. A strong gust of wind can sometimes tip over a whole section of fence.

"A jack fence is probably the easiest above-ground fence to build," Thomas says. "To keep it from tipping over you can hang a large rock under one of the jacks every so often, or make a small rock basket (net wire cage) under some of the jacks, with the jack secured to the cage."

Fencing can be a difficult challenge in the rocks, especially when it's too rocky to dig post holes efficiently, or to set posts using a tractor-mounted driver (post pounder).

Michael Thomas, who ranches in Lemhi County near Salmon, ID, has been building fence all his life, and has also done custom fencing for other ranchers. In some situations the only options if you have to set a brace post in the rocks are to dig out the hole with a backhoe (in terrain where you can get the machine to the fence), or keep chipping away at the rock (if it's a type of rock formation that will chip and break) or prying them out with a hand bar if it's on a steep mountainside where you can't get to it with machinery; or in some instances, use a rotohammer electric drill that runs off a portable generator. These work well for drilling a small diameter hole into a solid rock ledge, to insert a steel post, or even to create a large enough hole for a wooden brace post, says Thomas.

In some types of terrain, however, where it's not too steep and there are a lot of surface rocks you can utilize an above-ground basket/cage full of rocks as a brace point to anchor your fence. You can gather and stack the rocks and then secure them with wire, or make a cage first and put the rocks into it.

"Net wire works fine to create the cage around the pile of rocks, to hold them in place," says Thomas. "The rocks are heavy enough that you only need to make a cage about three to four feet in diameter or width, to give you a solid anchor. You can secure your fence wire to the rock cage and stretch it from there."

This gives enough weight to hold any fence securely. If terrain is too rocky for setting wood posts, you can usually put steel posts into the ground far enough to hold, using the rock baskets every so often for braces.

Other strategies for rocks, if using a post pounder to set wood posts along a challenging fenceline, is to use a metal "post" to create a pilot hole. The metal post will often go down through rocky ground if it's not solid bedrock, pushing aside the rocks, or penetrating frozen ground, whereas a wood post would be forced out of line or just shatter. One of Thomas' neighbors made a seven foot tall metal pilot post to create holes for wood posts in difficult conditions, and several ranchers (including Thomas) have borrowed it on occasion when they have a tough fencing job.

"The post for making the pilot hole is like a regular wood post but is only about three or four inches in diameter and creates a hole to put the wood post into," Thomas says. "The pilot post is hard/solid enough that you can drive it into just about anything but solid rock. The pointed bottom part is solid steel about three feet long, and the rest of the post is hollow, like well casing."

This makes it a little lighter to carry around, but it's still very heavy.

"The top has a solid cap on it, for the post pounder to hit," he says. "You can drive that pilot post down as far as you can and then pull it out with the tractor loader, and insert your wood post into the pilot hole and drive it in - forcing it into the slightly smaller hole - and the post will be very solid and secure."

Other alternatives are a completely above ground fence such as a jackfence (buck fence) or worm fence. A worm fence is created by stacking logs or large diameter poles upon one another, interlocking in two directions. The finished fence is a continual series of corners/angles. This type of fence is safe for cattle but not for horses, since a horse may be injured if it gets crowded or chased into a corner by a herdmate.

A jack fence of poles works well where the ground is too rocky to set posts, but in windy country this type of fence must be anchored securely so it won't blow over. A strong gust of wind can sometimes tip over a whole section of fence.

"A jack fence is probably the easiest above-ground fence to build," Thomas says. "To keep it from tipping over you can hang a large rock under one of the jacks every so often, or make a small rock basket (net wire cage) under some of the jacks, with the jack secured to the cage."


Explore Related Articles

Trending in: Home

Trending Sitewide

Tri-State Livestock News Updated Aug 14, 2012 03:44PM Published Apr 27, 2009 05:41PM Copyright 2009 Tri-State Livestock News. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.