Stuart Island State Park is a captivating destination located in the state of Washington, offering an array of attractions and natural beauty to explore. Situated in San Juan County, this 433-acre park can only be accessed by boat or seaplane, adding to its remote and tranquil appeal. Here is a summary of the park, its points of interest, interesting facts, and the best time of year to visit, based on information from multiple independent sources.

Reasons to Visit:
1. Natural Beauty: Stuart Island State Park is renowned for its unspoiled natural scenery. Visitors can marvel at stunning forested areas, rocky shorelines, and pristine beaches.
2. Wildlife Watching: The park is home to a diverse range of wildlife, including deer, bald eagles, seals, and various marine species. Birdwatchers will also enjoy spotting migratory birds passing through the area.
3. Recreational Activities: Visitors can engage in a variety of outdoor activities such as camping, hiking, picnicking, kayaking, fishing, and boating. The park offers a picturesque backdrop for these pursuits.

Points of Interest:
1. Turn Point Lighthouse: This historic lighthouse, built in 1893, stands on the park's northern tip. It offers panoramic views and is a great spot for watching sunsets.
2. Prevost Harbor: A well-protected anchorage, Prevost Harbor provides opportunities for boating, swimming, and beachcombing. It also features a dock and moorage facilities.
3. Reid Harbor: Located on the east side of the island, Reid Harbor offers stunning views and ample opportunities for boating, fishing, and camping.

Interesting Facts:
1. Stuart Island State Park is part of the San Juan Islands, which lie along the Salish Sea between Washington State and Vancouver Island, Canada.
2. The island was named after Frederick D. Stuart, who explored the area in the 1840s and later became the first customs collector of Puget Sound.
3. The park was officially established in 1954 as a state park and is managed by the Washington State Parks and Recreation Commission.

Best Time to Visit:
The best time to visit Stuart Island State Park is during the summer months, from June to September, when the weather is generally pleasant and conducive to outdoor activities. The park tends to be less crowded during weekdays, providing a quieter experience. However, it's important to check weather conditions and plan ahead, as the region can experience rain and fog at any time of year.

Sources:
- Washington State Parks and Recreation Commission: https://parks.state.wa.us/677/Stuart-Island
- San Juan Islands Visitors Bureau: https://www.visitsanjuans.com/destinations/stuart-island