I read one time that some Rocky bulls were planted in SW WA.
I read that too. On this thread 
It's on the internet it must be true.... They can't put anything on there that isn't true, right?
?

"Coastal Plains and Mountains
We collected data from 4 elk herds west of Interstate 5 in western Washington that we refer to as
(1) Forks (10 km north of Forks on the Olympic Peninsula [48o 00’, 124o 22’]), (2) Wynoochee
(50 km west of Olympia [47o 15’, 123o 38’]), (3) Chehalis Valley (30 km southwest of Olympia
[46o 50’, 123o 20’]), and (4) Willapa Hills (75 km south of Olympia [46o 30’, 123o 10’]). In
general, elk herds in this region are presumed to be the Roosevelt subspecies (C. e. roosevelti),
although elk of the Rocky Mountain subspecies (C. e. nelsoni) were transported and released
near the coast, at least in western Oregon, just after the turn of the century (Harper 1987)."
https://research.wsulibs.wsu.edu/xmlui/bitstream/handle/2376/2887/Cook_wsu_0251E_10121.pdf?sequence=1 This isn't the document I read it in, it was something else that used to be on the WDFW site. But this reference to Harper might be where the WDFW info came from, although this excerpt only references Oregon for sure.