I was looking at BIGHORNS and found these. Tread is a bit deeper than BH, and price to my door was about half BH.
Radial ride and a handling at 4PSI is same as BH, and these run true to size, perhaps a hair more.
Add the terrific bead protection and 8 ply rating and have a great, TOUGH tire.
For this tire to fit your 2005 Rancher you would need a 12" rim. With how common it is to modify the wheel and tire size on ATV's, tires will get profiled to fit many units because technically they can fit with the correct wheel. We have no way to determine what size wheel you may be running so we do provide the specs for the stock wheels/tires and ask that you do verify what you have before placing the order so receive the correct items. If you do have the stock 11" rear wheel, you will need to look at tires that are designed for an 11 " wheel, which can be found here : http://www.motosport.com/utility/tires?rimSize=11~
Unfortunately you are not going to find an 8 ply tire that small. The 8-ply tires are designed for UTV's and the largest ATV's. None of them will use a tire that small. Your best bet is going to be to go with a 6 ply tire. Even those tires available in that sizing are very limited to the ITP Mud Lite, and the STI Black Diamond radial.