PenmanPhoto
What time of year and how long are you looking to make the trip.
Judging by the name I assume you're looking for photo opportunities? what do you like taking pictures of?
I've done both the I70 and I80 routes between Denver and NYC. Along the I80 route you'll find Cuyahoga Valley National Park just south of Cleveland. Many Waterfalls, birding opportunities, and beautiful scenery Esp in the Spring or Fall. I've stopped there a couple of times and always wanted to get back there as a destination rather than just pass through.
Also near by is Marblehead Ohio which has a small state park surrounding the lighthouse. Good sunrise and sunset shots here if conditions are right.
Indiana Dunes National Lakeshore offers lots of beach and forest pictures mostly at sunset. Lots of hiking trails. another place I'd like more time to explore.
Lake McConaughy just north of Ogallala, Nebraska. Offers camping on the beach. (Beware that many areas around the lake are soft deep sand that can look just like perfectly fine hard pack. Easy to get stuck and expensive to get pulled out. Bring your sand ladders.) Good camping and fishing here, I like to camp on Lake Ogallala as the wind can be wicked on the beach camping areas. Good birding site in the Spring or Fall. Lake tends to drain through the summer so best water recreation and beach camping is usually early summer.
If you get off I80 in Sterling and head West on Co-14 you'll come to the Pawnee National Grassland. It's an interesting National parks unit that is basically untouched prairie. Can be a good dark sky site for star watching if the local fracking rigs are not drilling, pumping, or burning. Keota Co. is a small "ghost town" with some old buildings that can be used for photographic interest. you can take Co-14 Seat to Fort Collins.
Co-14 will continue through the mountains north of Rocky Mountain NP. No access to the park but lots of little forest roads to explore off the sides of this route.
https://apps.fs.usda.gov/TravelAccess/# can be helpful in finding cool side roads to explore.
If you are visiting Denver head south on I25. Estes Park tends to be MOBBED in the summer. I'd suggest taking Hwy 7 / Peak to Peak highway south and entering the park via Wild Basin. It's a quick hike to Copeland Falls from the wild Basin Ranger "station"
From Hwy7 stay on the Peak-to-peak towards Nederland on Hwy 72 to the west you can visit Brainard Lake. Also check out the Rollins Pass road. It used to be a through trail but has been closed at the top for years since the Moffet tunnel had a cave in. Now it's an easy 4 hour out and back beautiful drive and fun 4wd trail. East side tends to be busy on the weekends in the summer due to proximity to Boulder and the Front range, west side is less busy.
Boort