Probably do not need detailed plans

If you still have the Walthers kit you can get rough ideas for timber sizes and spacing from it. In real life a "small" stock pen would often be rather crude. Posts do not necessarily need to be absolutely vertical and the boards do not need to be straight. Just make sure the cattle can not get over, under or through the fences.

Just use some stock sizes of styrene (square or round posts with thin rectangular boards) and glue them together. Then paint them. If it is supposed to be fairly new, you can use a dark brown or almost black shade with a little weathering. As the wood weathers it would turn various shades of gray.

Small Stock Yard

In On30 I used a GC lazer kit (I think) for the ramp and then scratch built the stock enclosure. Have a look at https://bearwoodamrg.wordpress.com/on30-narrow-gauge/, scroll down to Sumach Grove and let the slide show roll. Towards the end of the slide show there are photos of the finished yard (as opposed to just the ramp structure).

Stock Yard

LSU Ag Center

Here’s a link to the LSU Ag Department with several plans for corrals, stock pens and cattle handling equipment.  

http://www.lsuagcenter.com/portals/our_offices/departments/biological-ag-engineering/extension/building_plans/beef

A number of agricultural universities have these kinds of plans, as well as other ag, recreational and residential related structures available on-line.  Some of the plans date back to the 1930’s.  Here’s link for the main page, 

http://www.lsuagcenter.com/portals/our_offices/departments/biological-ag-engineering/extension/building_plans

Lou in Utah

Great Northern Stockyards and Stockpens

I will second, RMeyer's comments. I would not use a kit and would use a variety of boards, posts, and other assorted lumber. Assuming you are modeling pre-1970 when rail stock operations generally ended, they would be of wood construction, with multiple changes, repairs, and pen sizes over the years. Usually the only design drawings created were pen plans and gate/chute details.

Lou posted some nice drawings but remember that cattle loading and holding facilities have advanced dramatically in the past 40-50 years, particularly in standardization and metal construction.

I have attached assorted drawings of GN facilities, but these should only be used as a guide. It is not likely accurate to what the railroad even built at the time.

http://www.gn-npjointarchive.org/_layouts/15/start.aspx#/Lists/BN_Structure_Drawings/AllItems.aspx?View={F6F834F3-1010-4F18-9089-2D576053E92F}&FilterField1=Structure&FilterValue1=STOCKYARD

Feel free to ask me more questions if you have any. I'm not in the cattle industry but I am an architect that has been drawing and documenting historic ag buildings and structures (including cattle pens) in Northern Colorado for the past 4 years.

I took several pictures

I took several pictures of the stock pens out in Chama New Mexico. These were used mostly for sheep. The sheep pens had the double shoots (High and Low) because the stock cars for sheep had double decks. 

I uploaded a few pictures to my Flickr picture sharing account. You can click on any of the pictures for a larger view and then use the right arrow to move to the next picture.

https://www.flickr.com/photos/23101722@N06/albums/72157646932619560

Bill B.

Stockpen drawings

Richard noticed your CNW logo. Each railroad actually did have standard plans for stockpens and loading chutes. You will find a number of railroad historical societies have published them in standard plan books. I have collected quite a few images for railraods in the upper midwest, ie livestock territory, including some for the CNW. You can also find drawings and photos in the ICC Valuation reports available at the National Archives in College Park, Maryland. The ICC reports are quite detailed, and a study of them will show that the size and spacing of fence boards and posts varied among railroads.

Most pens were sized to hold the contents of one or two stockcars. this is the reason you will see multiple pens at locations that shipped lots of livestock. A common pen size was 48'x48' on the Rock Island. I have seen 24', 32', and similar lengths. The lengths were dictated by the post spacing, which varied per railroad. I will attached a few drawings to give you an idea.

Stockpen Drawings 2

Just noticed that one drawing I posted does not ID the railroad. It is from the Frisco showing pens 1, 2, 3. When I first started looking for stockpen drawings, some 35 years ago, it was a challenge. But Historical Societies and the internet have made the task much easier. Many drawings I have are too large to post. But if you are more specific in your request I might be able to help. Just noticed I posted the CNW chute for unloading trucks. Below is the CNW stockpen drawing.

...

Check out HOseeker.net for the plans to Campbell's stock pen kit.

http://hoseeker.net/structures.html Scroll down to Campbell Structures, then drop down to 781 Cattle Loading Pen.

Buy the wood, stain it, put it together, it's about the best way you can go.

@Benny

Cool website, Benny, thanks!  I'll be referencing that when I build my stock pen, and many other structures too!

Stock Pens

I scratch built stock pens to fit into the space I had available for it on my layout. It really isn't difficult. I live in Montana and have been around quite a few over the years. The plans posted above should give you a good idea.

More photos, Montanan?

Montanan,

Do you have more photos of your layout? It looks good and I'm always on the lookout for more Hill line layouts.