There is something for everyone on Grotpeter trail. This is the heart of Castlewood State Park. This trail is fun for intermediate and advanced riders and has plenty to challenge beginners! From the start of the trail, there's a short melow climb into a nice swithchback into a steeper climb that will get you working.
From the top of the climb to Ries Rd there is nothing but good flow and hard pack to think about. After crossing Ries is where the beginners will be challenged and the more advanced riders will have some fun with a steep rooted downhill into a rutted climb up to the top of "Cardiac Hill!"
Take it easy down Cardiac Hill, it is a steep straight descent on large jagged rocks, if you go down here you'll know it! Cross Keifer Creek Rd and you'll have a nice ride back to the start along the banks of Keifer Creek. Keep an eye out for local wildlife on this section as they come up for a drink of water.