Hey Bill,
Been a while since I've done that one, but I'm sure the geography hasn't changed too much ;) As I recall, there's a goodly elevation change, some rocky parts to cross over, and there's also a descent to Odessa Lake itself. East side of the lake was "meh", but the west side was beautiful. Probably where those pics were taken. Lake itself is over 10000 feet, and the rocky sections of the trail are not recommended for small children, so depending on the age of your grandkids, it might be a challenge for them. Hike out and back was a little over 8 miles. This is if you use the Bear Lake Trailhead and parking area. There's also the trail from the Fern Lake Trailhead that goes to Fern Falls and Fern Lake and then continues on to Odessa Lake. Haven't done that one, but it's pretty much uphill all the way to Fern Lake.
An alternative you might want to consider (if you've not done it before) is a loop trail. Take the Alberta Falls Trail, but continue on up the Glacier Gorge Trail to the Haiyaha Cutoff Trail, and take that to Haiyaha Lake. There's a lot of hiking in the trees, so parts of it are sort of "meh", but there's open areas that have good views. Haiyaha Lake wasn't our destination though.
Continue on past Haiyaha Lake to Dream Lake. From there you can also go up to Emerald Lake, then return to Dream, and head down to Nymph Lake and back to the Bear Lake area. Downhill pretty much all the way from Dream past Nymph and on to Bear Lake. And the distance is about the same, 8 miles; maybe closer to 9ish if you add in Emerald Lake from Dream Lake. We did this loop with a couple of teenage girls (carrying their purses -- that was a sight!). There's some areas where there's a bit of a climb, but there's also some goodly flat areas. Lots of good photo ops as well.
Whichever you choose, HAVE FUN!
