Just after discovering the original Montrail Hardrock, which fit me perfectly, I found out that Columbia Sportswear had bought them out in 2006. The first year or two, Columbia evidently used the same last, and the shoes worked well for me. I tried the Columbia version for a couple years after that and returned them because they didn't fit (way too big in the heel). Then Columbia discontinued the model altogether. None of the new models worked for me at all. I wrote to their customer service, who told me that one of the new models was identical to the old Hardrock. It wasn't--too wide in the heel, too narrow in the toe box! They made me so mad that I still won't buy anything from Columbia even though, for me, it's a local brand. (Their stuff is on the heavy side anyway.)

I would not count on any of the current Columbia shoes to be any relation to your old Montrails, but you could try them on. Everyone's feet are different, and mine are, admittedly, really weird.

I now have to stick with New Balance, whose SL-2 last fits my feet, having the narrow heel, wide and high toe box, antipronation and motion control features I need. It's available only in standard street runners and street walking shoes, though, so the tread is a bit skimpy for rough trails.

You might want to visit a good running shoe store (REI carries so few that I wouldn't bother there) and plan to try on a lot of different brands and models of trail runners. Unfortunately, the barefoot, zero-drop fad has hit a lot of trail runners, but there still are some that might work.

Good luck!