Highback Beartrap Roping Saddle 15 Wide Tree Custom - eBay (item 170561537244 end time Nov-13-10 10:28:22 PST)
The swells (front of the saddle) on a bear trap jut out and are swept back to keep the rider in place. But because of the high cantle, it is a high-back.
I couldn't find any saddles listed as "loop seat" on eBay, but if you put in "high back saddle" you will find many similar saddles, in all price ranges. I think the maker of the saddle is what gives it value, along with condition. Yours looks to be in pretty good condition for it's age.
I checked my book "Saddles by Russel H. Beatie," and it says that loop seats started being made around 1885 and were popular up to around 1920. Your saddle also has "Texas skirts," which just means that it was the style of large, square skirt popular in Texas. (In contrast, round skirts are called California skirts, because they were popular there).
Well, that's about all I know, lol!