Hello,

This will be a challenge at 7,400 feet.  There are many recommendations to keep livestock tanks from freezing online, but I do not know how reliable they are.  The following resources are from Iowa State University and the National Sustainable Ag. Information Service:

Iowa State University -- https://www.extension.iastate.edu/smallfarms/protecting-water-freezing

Freeze Protection for Watering Systems http://citeseerx.ist.psu.edu/viewdoc/download;jsessionid=63C7E0A8A376976BA331A10C8559F305?doi=10.1.1.674.2050&rep=rep1&type=pdf

Jason Ahola, Colorado State University Professor with Beef Production Systems, shared additional information:

-          The best option is probably a propane stock tank heater (https://www.murdochs.com/products/livestock-agriculture/livestock-equipment/feeders-waterers-tanks/parts/trojan-66b-propane-stock-tank-heater/?utm_source=google&utm_medium=cse&utm_term=9257167&gclid=Cj0KCQjww8jcBRDZARIsAJGCSGuwBGLIHa-PQ2TQxSDEm3Ppah_v_11_51IacWC291i8iPlJmo4lDGYaAlt4EALw_wcB)

-          A bubbler (made for livestock, kind of like on a fish tank) that bubbles up and will kind of mitigate freezing, but it won’t work in extreme cold.

-          I think a good option is to bury a tractor/loader tire into the ground that is made to hold water via having concrete poured on the bottom, and then a relatively small hole cut in the side, kind of like this one (https://wrongdirectionfarm.com/2014/09/30/cattle-proof-water-trough/ ). It works by keeping most of the water in contact with the warmer ground, and only allowing a portion of the water totally exposed to the air/cold. It needs to be well-buried into the ground, and may be pricey (to buy tire, bury it, and cutting it is difficult).

I hope one of these suggestions will work for your operation.