Rock and Log Step Construction

Last revised: March 08, 2007

Trail Maintenance:
Rock & Log Step Construction

Copyright: Appalachian Trail Conservancy

Trail construction such as waterbars, ladders, and rock and log steps are future maintenance headaches as well as intrusions in the wilderness and are best avoided through careful trail design.  But, let's face it, these constructions are frequently necessary along the Trail, particularly to stop erosion, or lower the tread grade; so it pays to install them properly to get the maximum life expectancy from them and to provide the most elegant solution possible.

Rock and Log Steps Are Frequent Sources of Trouble

A step should be easy to walk up and down with a full backpack.  The most frequent problem with steps is they're made too high, and many or most hikers will use an uncomfortable step only if it is the only place to go.  I have seen many erosion-resistant steps with grass growing in them, while an eroding gully next to them received the majority of hiker use because the STEPS WERE TOO HIGH!

Steps should offer a flat place to walk immediately above and below each step and should be no more than 6 to 8 inches high.  The distance between the steps in a flight is also important.  The steeper the grade, the closer together, horizontally, they should be.  A curving flight of steps looks better because it looks less manmade, and it also offers variation in the distance between each step so that hikers of varying strides can be accommodated comfortably.

To begin construction, always start at the bottom of a flight of steps.  A flight of steps should be walked repeatedly as each step is added to make sure the distance between the steps is comfortable for a variety of hikers.  Or, for the more scientific, there are tables, available from landscape architects that give the appropriate distance between the front of adjoining steps depending on the grade.

Log Steps

Log steps should be made from the most rot-resistant wood available.  Either round logs or logs split in half can be used.  An 8-10 inch diameter is best so that the logs can be seated in a shallow trench to give them added stability.  The tops of steps should be as level as possible.  Steps can be any length, but should be long enough to extend past both sides of the tread.  The minimum size should be about 2 1/2 feet.  A 2 1/2-foot step provides an 18-inch tread between the stakes which anchor the step.  The stakes should be about 6 inches In from either end of the log, set into shallow notches cut in the face of the log, and driven into the ground about 2 feet.   Stakes that are too short are like no stakes at all.  They must take the pressure of significant pounding from the feet of heavily laden backpackers.  They should also be cut off flush with the top of the step to prevent the snagging of pant legs.

The tread between steps is compacted backfill and should slope gently up to meet the next higher step.  Steep slopes between steps are a sign that more steps are needed.   When wet, steep slopes can be dangerous.  If the grade to be climbed with the steps is very steep, consider using a log ladder instead.

Rock Steps

The typical failing in the installation of rock steps is using rocks which are too small.  Rocks used must be substantial enough not to move when jumped up and down on when in place.

Rock steps can be built in two ways: flat, overlapping rocks, or rocks set on edge in a manner similar to log steps.  Either way works fine, with the latter more efficient where rocks are at a premium or the slope is more gradual.  Again, the steps should be kept to 6-8 inches high.

When building rock steps with the rocks set on edge, be sure that 1/4 to 1/2 of the rock is buried in a trench to provide a good foundation, with the thick side, if there is one, in the trench.  These measures help to keep the rock from sliding down the hill.   This type of rock step should also have the top tilted back uphill, so that hikers stepping on the rock do not push it forward and knock it loose.

Overlapping flat rock steps, when properly located, look very natural and will last virtually forever.  Rocks should be carefully chosen so that the steps offer flat surfaces to walk on with ample area to step upon.  Steps of this type should rest on shallow concavities when on soil.  This allows the rock to be supported on four points to prevent rocking and eventual dislodgment.  This type of rock step should not move when jumped upon.  There is a great temptation to shim large rocks with smaller ones to prevent rocking, but frost action and erosion will surely work the smaller rock loose.   Extreme care should be taken when working with rocks to assure that no one's hands or feet are crushed.  A crowbar and pick-mattock are the rockstepper's tools and make the job easier and safer.

A coweeta dip or waterbar should be placed immediately above a flight of steps to give extra protection against erosion.  On a particularly long flight it is advisable to insert a coweeta dip or waterbar in the midst of the steps, as well.  Any water flowing along the steps should be directed over the center of the steps instead of along side of them.  Their center is where they best resist erosion.

If these "steps" are followed, a good set of long lasting steps can be installed.  For more information on step construction, see the A.T. Stewardship Manual, Trail Design, Construction, and Maintenance, available from ATC.

--Morgan Sommerville