I don't think the 1/2 mile is a problem at all - that's about what it is from my woods where they outwinter to the corral and winter hay feeding area. The waterer is about 1/2 way. The exercise is good for them.

On the waterer I am not familiar with the electricity free ones. HoweverI have had excellent experience with a Petersen concrete waterer. I assume by your name MSU that you are in Michigan? Depending on if you are able to check the waterer every day you might try a nonelectric model. If you can't check it every day then I would use a properly installed electric model and do what ever it takes to install an electric wire to the waterer area.

For 50 head it is worth doing it right the first time. The cattle really need a source of non frozen water at all times in the winter. Eating snow is a last resort.

Here is a picture of my Petersen I took this past January in WI when the temp was about 20 below zero and right after a snow storm. It got down to about 30 below a couple nights this past winter. If you take the time amd make the investment to install it right it I think you will be thankful later, especially for 50 head.  This waterer would be fine for 50 head. There is no way they can all drink at the same time. They will go in groups when they get thirsty.  What breed are you working with?

Jim at Dawn  

edit: I think the key to success with a northern waterer is in the installation details. here are a couple other photos.

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IMG_0005_1.JPG (82KB - 157 downloads)

IMG_0861_small.JPG (73KB - 164 downloads)

05-06-07_1348.jpg (83KB - 164 downloads)