I keep going back to this lady.
Everything she was wearing had the same colors - blue, red, tan man's plaid shirt; tan OP (Ocean Pacific) vest; blue/white Nikes (size 5 - if men's shoe, that's equivalent to about a 7 in women's sizes); Calvin Klein blue jeans; white tube socks with red stripes, red bandana around her ankle, and even the burgundy/maroon shirt was in the same color palette. She cared about how she presented and was modestly dressed.
I do note there were no undergarments mentioned - perhaps she didn't wear them. All clothing and jewelry is indicated as being on the body.
Avg lows-highs for the area in May-June 1984 were lower 50s (with some in the 40s) and highs in 70s/lower 80s.
The described location of her body is a popular area for hikers and river activities, as per this website:
49ER Crossing. I don't know the history of the park, but there is camping there now.
South Yuba Recreation Area
Given her clothing with avg temps, the location/discovery of her body, LE's assertion that she was "transient, from out of the area", I'm wondering if she didn't go there to enjoy the park with someone who then took her life.
Concerts in Nevada County (at the fairgrounds) were ongoing. Grateful Dead played there in 83, and Crosby, Stills & Nash headlined Sierra Sun Music Festival in Sept 84. LE also mentioned she may have been in the area for a concert. I'm looking for historical archives for the time period she was discovered, please post if you find any