Great Bang for Your Buck!
Hiking from US-93 to Kaiser Hot Spring is easier than hiking in the Phoenix Mountains Preserve. Seriously, anyone without a zimmer frame could do it.
From the trailhead, pass through the gate and under US-93. There is a trail down to the wash. It's a bit slippery, but only 30 ft. and not bad. Once in the wash, follow it west.
The plastic sheet-covered lean to at 0.9 miles is collapsed to trash.
FR 7519 connects to the wash at 1.0 miles. If you want 3.8 extra miles, and a little more AEG, do a loop up FR 7519. (Techinically not a forest road, as this is BLM land.) There's some awesome views from up on that unnamed mesa.
The route has been sandy to this point, but is generally hard pack dirt the remainder of the way to Kaiser Hot Spring. Also, the canyon past FR 7519 is SPECTACULAR. Seriously, take your time: Look backwards, up & around. It will blow you away.
There's also lots of caves to explore, some without too much climbing.
The hot spring itself is warm, not hot, and fed by a hole in the rock that was gushing water when I was there. The overflow trickles down canyon another ¼ mile to Burro Creek. Past the hot spring, there are "No Trespassing" signs for what appears to be a current mining operation. (Though no one was present when I visited.)
Kaiser Hot Spring itself is not large, but it is safe & soft to walk in without shoes. It is calf deep, so you can sit in it & soak, but not swim.
Check out the Official Route and Triplog.
Gate Policy: If a gate is closed upon arrival, leave it closed after you go through. If it is open, leave it open. Leaving a closed gate open may put cattle in danger. Closing an open gate may cut them off from water. Please be respectful, leave gates as found.