Need help locating highway with steep inclines

I use both Garmin and Streets and Trips to route my trips. We have been up several steep grades like I 70 out of Denver. Are there any Points of Interest POI that would help me avoid these steep grades. Example when we leave Michigan for Los Angeles, I would not mind driving a few hundred miles more to prevent those steep grades. Any suggestions would be appreciated. I hate to slow down to 35 mph trying to get up those grades even though I have plenty of company with the trucks. Easier to sit here at home planning than in the car when we see the sign indicating steep grade.