I just wanted to hop on and shed some light into the area where these remains were found. FYSA I lived in Yelm from 2017-2020 and travelled daily on this stretch of road to Lacey and JBLM.
The google-esque pin is on Church Kalama road. Church Kalama == Peter Kalama, where the remains were found. If I'm incorrect in assuming this, or someone knows more specifically where other parts of the remains were found, I'd be happy to update the map.
To get your bearings, this section of 510 connects Yelm (as well as Tenino, Rainier, and Spanaway) to Lacey via the Nisqually reservation. This is an 'open' res with Thurston county transit buses regularly stopping at the Red Wind Casino. I marked the Nisqually jail in the upper left corner of the map. I wouldn't say tribal police presence is strong, but they're there. They have a lot of forested area to cover, so that's probably why I didn't see them patrolling too much. There was always a patrol car at the casino, but not always a LEO in the car (probably was inside the casino).
The orange rectangle I marked is where a homeless camp is located. You can see this camp from the road, but they try to give themselves some privacy by staying back into the trees. I would often see people walking to and from this camp and the casino (it was pretty easy to tell that a lot of these folks struggled with addiction). Sometimes there were also camps SE of where you see 'Leschi's Best' marked on the map. Camps in this location were often broken up because there's now a huge clearing there that JBLM uses for night training missions.
Up north of the Nisqually river is reservation and JBLM land inner mixed. There's a dirt road called 'Tank Trail road' (sometimes marked on maps, usually not. Sidenote this is the dirt road used to direct civilian traffic through base when the Amtrak derailed in DuPont in 2018). You could probably access this area from Tank Trail road, but I would guess Nisqually police would see you.
Back in 2017/2018 I was training for a ruck and would be all over this section of the ranges. I had base access, but there's no checkpoint until you get right up on base. Otherwise you can hike around in here via east gate road through Roy. If you find Lewis lake on a map, there are lots of tank trails that can take you back into this section of the res. I found myself in this section on accident a few times. To give you an idea of the size, my pace was about 18 min/mile and I could go 4+ hours without seeing anyone back in here (on a weekend at least). Looking back I shouldn't have hiked alone as a woman for that long, but hey, I lived to tell the tale.
Hopefully this gives some Websleuths an idea of the identity of the woman or her killer. I could easily see either of them as being part of this homeless population, or her killer as being a soldier or veteran. A soldier would know that this piece of land is pretty desolate and access is somewhat controlled. He/she would also know where land nav courses and common camps are and to steer away from them. Additionally, s/he would know how easy it is to pop back onto a dirt road that connects to 510 or east gate from this location.
I saw a few mentions of Chehalis and Centrailia missing persons cases. I don't see someone dumping remains here from Chehalis or Centrailia. Those areas are probably even more desolate than this section of the res and base. I could see someone from Lakewood, Tacoma, Lacey, (maybe Graham and Puyallup?) Yelm, Tenino, Rainier, Olympia, Roy, McKenna, or University Place ending up here.
I hope she gets her name back soon.