After thorough research from various official sources – primarily, the U.S. Department of Agriculture's Forest Service – following is a list of specific trails within the Monongahela National Forest that have been explicitly stated to allow horses. 

1. Spruce Knob Lake Trail (#165)

Situated near the highest peak in West Virginia, this 1.9-mile trail should be on every horse rider’s bucket list. Enjoy the ride amidst whispering spruce trees and a clear mountain lake. 

2. Seneca Creek Trail (#515)

This trail is 6.7 miles long with a large campsite at the trailhead. With the beautiful stream of Seneca Creek running parallel, riding here can be quite peaceful. 

3. North Fork Mountain Trail (#501)

This is a challenging trail of approximately 24.1 miles. It's recommended for experienced riders due to the dramatic shifts in terrain and high elevations.

4. High Meadows Trail (#259)

This 5.8-mile trail located near Circleville, WV, is known for its excellent vistas of the Potomac Valley. A pleasant trail for horse riding during the summer months.

5. Brushy Ridge Trail (#267)

A shorter trail of 3 miles, it's the perfect trek if you're up for an easy ride while enjoying the serene beauty of the forest. 

6. Leading Ridge Trail (#254)

This 5.2-mile trail is relatively gentle with few steep slopes, making a lovely horseback ride for beginners. 

7. Endless Wall Trail (#248)

Despite being only 2.7 miles, this trail is notable for its panoramic views over the New River Gorge. It’s a thrilling horse ride that should not be missed.

8. Huckleberry Trail (#533)

This 3.8-mile trail attracts riders with its lush greenery and abundant wildflowers in the spring.

9. Boone Run Trail (#558)

This 2.4-mile trail is a tranquil ride with gentle slopes, dense forests, and a lovely creek.

10. Hampton Trail (#534)

This 2.4-mile trail offers a peaceful retreat with lovely views of the Gandy Creek along the way.

These trails give you a brief insight into what riding in the Monongahela National Forest would feel like. However, it's always advised to check for updates from the U.S. Department of Agriculture's Forest Service before starting any adventure. Specific restrictions or conditions might apply due to varying environmental circumstances or maintainance issues.

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.