Average grade can be deceptive sometimes if it's not uniform. I notice that you have Topo 5 (at least the elevation profile comes from Topo 5). If you display both route and profile and run the cursor along the route, it will display the instantaneous grade in the stats box, and you can easily see the max and what you will encounter along the route - much more useful than an average. I think the stats will also display average grade as well, but my concern is usually with the steepest portion.