Wild shrub in Alberta

Please identify this plant,

It appears to grow on northern slopes in heavy bushed areas. I noticed it because of the beautiful coloured four petal flowers seen probably only at this time of year. Most plants appear to be only one meter tall and quite spindly with a few thorns. Attached is a scan of the picture of flower and part of plant. I have never seen this plant before. Calgary Alberta.

Skip Crockett

 

It looks like a Clematis columbiana, possibly var. tenuiloba.

 

I have checked out your findings and agree with you fully.

Thanks for your help.

Skip Crockett