Castle and Heart Lakes Trail Professional Review and Guide
"The science helps researchers understand some things about the world’s freshwater: how healthy it is, what’s happening to it, and how water quality can improve with time—and interference by people. What the budding researchers have found is that despite heavy year-round use, Castle Lake continues to be one of the most unspoiled subalpine lakes in the world. Start at Castle Lake and take this trip up to tiny Heart Lake, and you’ll have a great appreciation of these north state gems. This trek in fall offers up many fewer people, and you’ll be able to see the gradual color change, from greens to golds and browns. In the winter months, you’ll still be able to pick your way through the forest and up the ridge, but if the snow is too deep, you can satisfy your exploration needs by following the western shoreline of Castle Lake."