I am planning on backpack hunting in the Mallard-Larkins up high in near Larkins Peak on the Unit 10 side opening week. I am thinking the tops of Bear Creek, Isabella Creek and Goat Creek. Do many elk cross back and forth from unit 9 to 10 and vice versa. If so I may also walk along the unit 10 and try to catch any before they cross the divide moving from feeding to beading areas.
That might be a pretty good strategy. The upper end of those drainages have some nicer open forage areas and the elk are likely hitting those early and late. The north-facing heavier covered areas on the unit boundaries will provide good areas for the elk to bed down. Catching them traveling between those areas might be pretty productive. I like your thought process! Good luck.