After conducting extensive research on official platforms, it can be confirmed that Gifford Pinchot National Forest allows horses on specific trails. Equestrian enthusiasts can enjoy sweeping vistas, stunning waterfalls, and verdant vegetation on these suitable paths. Here are the trails where horses are permitted:

1. **Pacific Crest Trail**: This famed trail winds through the heart of the Gifford Pinchot National Forest and is open to horse riders. The trail's incredible expanses and sceneries make it ideal for equine adventurers. 

2. **Indian Heaven Wilderness Trails**: As per official documentation, horses are permitted on trails in the Indian Heaven Wilderness area within Gifford Pinchot National Forest. This area is known for its beautiful meadows, stunning views, and seasonal huckleberries. 

3. **Goat Rocks Wilderness Trails**: The Goat Rocks Wilderness, according to the USDA Forest Service, allows horses on its trails. The region offers high-alpine terrain and fantastic views of Mount Rainier, Mount Adams, and the Goat Rocks area.

4. **Boundary Trail**: This trail stretches about 54 miles from the North to South of the National Forest and allows horses. It traverses multiple wildernesses and offers fantastic views of Mount Adams, Mount St. Helens, and Mount Rainier.

5. **Juniper Ridge Trail**: Horseback riders can access this trail, which provides grand views of Mount Rainier, Mount Adams, and Mount St. Helens. Furthermore, it offers a wide variety of terrain, from dense forests to rocky ridges.

6. **The Bluff Trail**: Horses are allowed on the Bluff Trail in the Gifford Pinchot National Forest. The trail offers delightful views of the Swift Reservoir and Mount St. Helens. 

7. **Cowlitz Valley Trails**: The USDA Forest Service states that horses can traverse the Cowlitz Valley Trails. These trails span across several environments, including old-growth forests, riparian areas, and high alpine regions.

In conclusion, Gifford Pinchot National Forest offers an array of trails suitable for horseback riders. These equestrian-friendly trails provide a fusion of natural beauty, unique terrains, and incredible views of the region's stunning landmarks. Remember to respect the land and follow a 'Leave No Trace' ethic to help maintain the trails for future enjoyment.

Please note that trail conditions and rules can change, so always check the current status and regulations with the U.S. Forest Service before planning a horseback riding trip.

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.