Free: Contests & Raffles.
Simply watch when and where the shade is and how it moves. The elk will mimic that movement by only a few minutes difference. That's a strategy that I use, anyway. That, and hunt close to water where the last of that shade either runs out or stays throughout the day. Google Earth's sun chasing time-slider feature is priceless for this info if you want to get a jump on info collecting. This happens May through November.