After conducting extensive research, several trails within Monongahela National Forest have been identified that allow horseback riding. Here are the pathways you and your equine companion can explore:

1. **High Meadows Trail:** This is a 5.6-mile trail that's welcoming to horse riders. The area features a River flowing nearby adding to the natural beauty of the trail. 

2. **Boar's Nest Trail:** Just 3.2 miles long, this trail is nestled near Marlinton, West Virginia. Not only is it open to horseback riders, but in the winter, it's also used for cross-country skiing.

3. **Alpena Gap and Robbins Run Loop:** This is a moderately challenging loop trail of 6.4 miles, great for the experienced equestrian.

4. **Cranberry River North Fork Trail:** Here is a much longer trail with a length of nearly 16 miles. With a diverse landscape of forest, wildflowers, and a river, it provides a pleasing spot for horse rides.

5. **Allegheny Mountain Trail (TR532):** This trail is about 16.5 miles long and offers scenic beauty with easy to moderate difficulty level. Horses are allowed to explore this trail.

6. **Forks of Red Creek Trail (TR509):** This trail also welcomes horse riders. With a length of approximately 8.4 miles, this trail offers diversity in flora and fauna, making the ride more interesting.

7. **Spruce Knob-Seneca Rocks National Recreation Area:** While not a singular trail, many trails within this area such as the Elza Trail (TR542) and the Huckleberry Trail (TR533) welcome horseback riders.

Please remember to always check with the local Forest Service or a ranger station before venturing onto any trails with your horse to ensure they are open and safe. Maintain good trail etiquette, respect wildlife, and leave no trace of your visit behind. 

This list provides a starting point for equestrians wishing to explore the beauty of Monongahela, and each trail promises a unique experience and stunning views. Happy riding!

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.