Access by boat only
I've experienced the hot springs and tubs at the Chief Shakes site three times. There is a reason why the locals "vacation" up the river and visit the tubs every year--it's exquisite scenery (no wonder John Muir was moved to write about it) and it's luxuriously out-of-place to be able to soak your woes away in the middle of nowhere!
The mosquitoes can be fierce here at times, but no worse than a Louisiana bayou or a Minnesota bog - just dress in light layers or bring bug spray if you use it. The hike in from the river is just over a quarter mile of pretty easy-going terrain. (The only obstacles on the flat ground are the tree roots than can present tripping hazards.)
There is an enclosed tub and an open air tub as well as two outhouses and changing huts. Otherwise, there are no amenities to be found since this is part of the Stikine-LeConte Wilderness.
You should hire a charter/guide service or know a local to make this trip. The river is tidal and has a lot of opportunity to leave you stranded or in pretty serious trouble. There are places to rent from or even tours to take from both Petersburg and Wrangell.
Bring a bathing suit and towel as well as a picnic! The trip should be planned into a full day or at least a long afternoon. You should try to get up to the nearby glacier of the same name as well as the Canadian border, since it's pretty neat to see and is only a few minutes further.
This is a special place that is an incredible experience for families - those with young kids might have trouble entertaining the littles if they aren't fond or accustomed to longer boat rides - it's a few hours even in a jetboat. Our three-and-a-half year old did great but we are constantly boating and he's used to being aboard boats.