Castle Lake is a wonderful spot to enjoy a hot summer day or evening and reap the benefits of outdoor life in Northern California.
The glacially formed lake and surrounding area offers a prime spot for water-based activities like flat water paddle sports, fishing and swimming. Originally the area was part of Shasta and Wintu Native American territory, and it lays not far from Battle Mountain, the site of a major land war. To them, the lake was known as the "Castle of The Devil" due to the belief that an evil spirit inhabited the lake during the winter (now known to be shifting ice). Today it is studied by University of California, Davis, and the Forest Service.
The lake itself is roughly 50 acres, making it a good size for those that own kayaks and stand-up paddleboards to take quick and easy tour of the lake. Due to its smaller size, it is most commonly used for swimming, picnics, and by those staying at the Castle Lake Campground just a few hundred feet away. It is also a great option to cool off in after returning from the Castle Lake Trail system. The site is stunningly beautiful, especially in the morning when the lake is completely undisturbed and visitors can meditate on the pristine granite and evergreen reflections in the lake. The sides of Castle Lake are surrounded with beautiful granite slopes covered in brush and evergreens. From the picnic area you will be greeted with a wonderful view of Castle Peak.
The picnic area does offer two tables and a moderate amount of flat and cleared ground for activities. The lakefront around the picnic area is also pretty flat, and it slowly dips into the lake, making it easy to wade out. The waters are crystal clear, with felled trees laying just below the surface. Because there is no sharp dropoff early on, this lake is welcoming, especially with increased visibility that allows you to stay aware anything below the water surface.
You can also use the Castle Lake Trailhead to reach a few smaller lakes like Heart Lake and Little Castle Lake. Just beyond Heart Lake, is the infamous Castle Lake Overlook. If you have the time and energy, treat your eyes at sunset by trekking up to Castle Lake Overlook from the picnic area. From the trail, and especially Heart Lake and the Overlook, you will be able to see possibly one of the best views of Mount Shasta in the region.