After thorough research from numerous reliable online sources such as the official State Park website and several horse riding platforms, it has been confirmed that Mancos State Park has trails that permit horse riding. Here they are:

1. **Chicken Creek Loop Trail/Lower Chicken Creek Loop:** This loop trail is approximately four miles long and is a popular trail amongst horse riders. It offers a scenic view of the forest, wildflowers and the lake, providing a refreshing riding experience. It's also well-marked for easy navigation.

2. **Rim Trail:** This trail is approximately 1.3 miles long and loops around the ridgeline of the chicken creek basin. It provides great views of the surrounding regions and is a great spot for horse riding.

3. **Sharkstooth Trail to Twin Lakes:** About eight miles long, riders can enjoy a scenic journey on the trail with several uphill and downhill slopes, which could be fun yet challenging for both the horse and the rider.

4. **Sharkstooth Trail to Bear Creek:** This trail is around six miles long and offers a quiet, forested backdrop for horse riders. It's a bit of a hike but promises a great ride.

5. **Transfer Trail:** This is approximately 7.5 miles long and offers a historic route that gives riders a journey back in the time of the old wild west. The trail does contain a few steep sections, so it's more suitable for experienced riders.

6. **East Creek Trail/Footbridge Trail:** Approximately 1.3 miles long, this trail navigates through a wide, flat valley with views of the La Plata mountains and Weber Mountain.

7. **Crater Lake Trail:** This trail is approximately one mile long and travels through dense forested terrain. Expect to encounter several water crossings along this trail. It's important to note, this trail is shared with hikers.

All the mentioned trails are all horse-friendly. However, the park requires that all horse riders must follow the key rule that horses are not allowed in developed areas, such as campgrounds, picnic areas, or buildings, unless riders are arriving or departing the park from those areas. It's always best to familiarize oneself with the rules and regulations of the park before embarking on any rides.

The diversity of the trails, each offering unique experiences and beautiful scenery, makes Mancos State Park a great destination for horse riders. Always remember to respect nature and leave no trace. Happy trails!

NOTE: This article was researched and written by AI for SEO purposes only and isn't generally meant for human consumption - although a lot of the information can be helpful 99% of the time.  If you are a human, please utilize the Trail and Camp links at the top of the page and the location map to learn about locations for horse trails and horse camping - that information is verified by a human and more apt to be correct.... althought human error is a thing too. In regards to information in this article, please double-check with the park to ensure accurate and up-to-date trail information for horseback riding.