I finally found some full resolution digital topographic maps for the area we’re going to be in Montana. For reference - the Montana State Library keeps a complete set of topographic maps availabe for download in TIFF and SID format here.

By using these maps I’ve put together an approximate elevation gain/loss chart for the trail. You can clearly see the 3 passes that we’ll have to do. I think the most surprising part is how high the passes actually are. The first and last pass we have to do almost hit 10,000 ft. In comparison the 1 pass that we did last time we went to Montana was only 8600 ft. So basically I’m going to be sucking wind - being that the elevation of Regina is only 1893 ft.

UPDATE:
Elevation gain per day is approximately as follows: