In addition to the Johnson/Eisenhower Tunnel climb and descent and the Vail Pass climb and descent, coming out of Golden there's a significant climb of about 7 miles, from I-70/CO-470 up to Evergreen Parkway area and not too far beyond that, there's a significant descent of Floyd Hill with a very sharp curve at the bottom where US 6 merges with I-70. The Floyd Hill descent in particular is interesting because you can actually see a lot of the descent ahead of you, and how steep it appears to be. Fortunately, it's 3 lanes most of the way down, but it is impressive. Once you get down, it flattens out quite nicely until you get to the climb for the Tunnel approach. Even steeper if you might want to go up and over Loveland Pass instead of using the Tunnels.
I've done this with an '03 Tahoe pulling about 6000lb trailer. I got in line with all the semis heading up, most of us doing 25-30 miles an hour with our flashers on. Got passed more than a few times by 3500 diesels pulling big 5ers. You WILL see you fuel gauge drop dramatically.