Blackrock Trailhead is the portal to the southernmost natural hot springs of the Sierra, Jordan Hot Springs. Several hot springs bubble out of the ground next to Ninemile Creek, and several of them have been dammed with rocks and sandbags to form pools for soaking in. While the pools are about 104 degrees and the perfect temperature for soaking, be aware that the pools are in dirt rather than sand or rocks, so the water is quite muddy. Also, the pools are down by the creek so the view while in the pools is fairly unimpressive. That being said, there is something magical about being in a natural hot springs in the mountains.
The trailhead, though remote, is accessed via paved roads, and the parking lot is ample and paved as well. Make sure you get your wilderness permit from the Blackrock Ranger Station at the start of the road that leads to the trailhead. There are no limits on permits, so no reservation is necessary. During the winter the road is usually closed due to snow, but it is almost always open by Memorial Day and usually earlier depending on the snowpack. The parking lot will be the highest point of the hike, and there is an easy 1.8-mile descent to Casa Vieja Meadow. Several streams fed by springs meander through the meadows, and the eponymous fish of the Golden Trout Wilderness can be found in them. There are several cabins around the periphery of the meadow, and they make a scenic backdrop for fly fishing. From the meadow the trail follows Ninemile Creek down almost 2,000 feet of elevation over 3 miles with several stream crossings that can be managed by rock hopping. The trail levels off for about a mile before the hot springs, and there are several abandoned cabins nearby that are the remains of a resort camp started in the early 1900s that housed guests and used the hot springs until the Wilderness Act of 1978, after which it was slowly dismantled.
The hot springs are well loved and used and are busy on weekends, but you may be able to find some time to yourself even on a busy holiday weekend. As with most hot springs, there will most likely be some nudity. When leaving the hot springs, if you want to rinse off, Ninemile Creek is just 10 feet away.
There are plenty of campsites around the hot springs even on busy weekends, and it is easy to find a secluded campsite if solitude is your desire. Most of the campsites have firepits built with rocks, and many have metal grates nearby that can be used to cook over the fire. Between Ninemile Creek and Redrock Creek, water sources are nearby and easily accessible.
From Jordan Hot Springs, a trail leads down to the Kern River. The trail is not heavily trafficked and can be lost easily at certain points, so familiarity with map, compass and GPS navigation is recommended. On the way to the river, a small private cabin at Soda Flat will be on the right. The cabin is well maintained and clearly being used. At the confluence of the Kern River and Ninemile Creek there is a small cabin and structure and outhouse that is functional. Just about a third of a mile upstream along Ninemile Creek is a two drop waterfall. The pools at the bottom of the falls are crystal clear and inviting but might require canyoneering equipment to access safely. The falls of the Kern River are also just upstream of the cabins.
There are no nearby roads to this part of the Kern River, so traffic is very light and there is plenty of wilderness to explore for those with the time and the energy.