Very cool, "secret" trail to hot springs. The map is a bit misleading, and I think it might be intentional to keep people from finding the springs. I'll do you a favor and explain where they are, but please do your part by not posting about this trail on social media!
When you come to a big chunk of concrete with some blue graffiti on it, keep an eye for a big warning sign a little further down the trail. You'll take a left there and cross the water, then continue along the trail to the hot springs. The landmark on AllTrails for where the springs are is NOT correct. The actual springs are located at the "Viewpoint" landmark on AllTrails.
Be aware that there may be some people soaking in the nude, though there weren't any when we went. Bring a towel and be polite. Try not to hog the springs for too long if there are a lot of people. Parking might get a little tight during peak hours. We didn't have too much trouble on a weekday afternoon.