The most popular destination for hikers at Lory State Park is probably Arthur's Rock. While there are several different trails you can combine to get there, most people take the Arthur's Rock Trail.
The Arthur's Rock Trail starts at the south end of Lory State Park (directions below). The trailhead has bathrooms, trash cans, a sign board with a map and a bench.
Start hiking the dirt path west, past the bench, toward a canyon. You'll quickly cross a bridge and come to your first trail split with the West Vailley Trail. Turn left here for the Arthur's Rock Trail. Note, the Arthur's Rock Trail is hiker-only. If you want to ride a bike or horse, you'll need to use the Timber Trail or Mill Creek/Howard Trails to get to the rock formation.
I think the best time of year to hike the Arthur's Rock Trail is spring, especially mid-May. The leaves are out on the vegetation, the flowers are starting to put on a colorful show at this elevation and as you walk, you'll enjoy the sounds of the creek next to the trail. The beginning of the trail has two bridges and three water crossings using rocks. Come in mid-summer and the creek will likely be dry.
The Arthur's Rock Trail starts in a lush canyon. At the back of the canyon, at a turn in the trail, you may hear the sound of a waterfall. If you hear it, it's worth taking the short side-trail to see the little, moss-covered rock with a small cascade. Then return to the trail and hike up.
At 0.3 miles and 0.6 miles along the trail, you'll come to well-marked trail splits. For this hike, stay on the Arthur's Rock Trail.
The Arthur's Rock Trail has a variety of everything -- lush forests, open meadows and about a half-mile into the hike, you should get your first glimpse of Arthur's Rock. Yes, it's that rock formation ahead and to the right. You're going to be hiking several steep switchbacks up the valley to get to the top.
About 1.1 miles from the trailhead, you'll come to a sign pointing you right for the overlook and pointing you left for the summit. Take the short spur trail to the overlook. The overlook is a rocky area with a great view of Horsetooth Reservoir and the surrounding area. After taking a break and taking in the views, it's time for the final climb to the top. You've got another 400 feet of elevation gain and 0.6 miles to go.
The last section of trail follows the bottom of the Arthur's Rock formation, then goes around the west side of it. At 1.6 miles, there's a trail split letting hikers know it's just another tenth of a mile to the top. You'll turn back east a short distance, then climb up a rocky "path" to the top. There's a trail here, it's easy to see the steps, but it's also steep and a little scary if you haven't done this kind of hiking before. Just watch you steps, take it slow and enjoy the adventure.
At the top, you can stay on the dirt in the trees or climb around on the rocks and explore. Like the overlook, the views up here are great. You can see a large portion of Horsetooth Reservoir and across the Eastern Plains. This is a pleasant place for a snack or a lunch before you return the way you came.
For maps, current admission fees and more, visit the Lory State Park website. Get more than 200 hiking trail ideas across the state here. Don't miss any of my trip reports, sign up for an email alert by clicking on subscribe at the top of this page and follow me on Facebook.
Details: The hike to the top of Arthur's Rock and back, via the Arthur's Rock Trail is 3.5 miles (with a little exploring) with nearly 1,100 feet of elevation gain.
Admission fee: $7 in 2014.
Directions: Lory State Park is about 16 miles from I-25 and Harmony Road. Because there are several turns and county roads, I highly suggest using the directions from the Lory State Park website.