Dolmens in Washington State?

I was talking to my daughter on the phone just now and she was telling me that dolmens have been discovered in the State of Washington. I tried to look it up through Google but was unsuccessful. However, instead I found this interesting article on a mastodon skeleton discovered in Washington near Sequim with a proven spear point in it's ribs from a human. Here is the documentation of how it dates back 12,000 years and was buried under the Ash of Mount Mazama:

This situation changed in 2011, when a new study of the remains definitively concluded that Gustafson was right as to both the age and the human origin of the point.^[6] Along with the point, Gustafson analyzed the position of the 6,800-kilogram (14,991 lb)^[3] fossil, which was lying on its left side, while the heavily fragmented skull was rotated 180 degrees from its natural position. Noting that this could not have occurred due to natural causes, Gustafson deduced that the carcass must have been tampered with by humans.^[7] In addition to the possible evidence of human/mastodon interaction, archaeologists were surprised to find a mastodon in the area at all, because pollen samples that were taken showed no evidence of trees, which mastodons fed on.^[8]
In an excavated layer above the mastodon, as well as that of a 6,700-year-old deposit of ash from the eruption of Mount Mazama, a projectile-point was found in the style of Coastal Olcott points common in the area no earlier than 9,000 years ago.^[9]
The site also turned up remains of caribou, bison, and plant macrofossils.^[10] Bones of the bison showed evidence of butchering by humans.^[11] The pollen found in the same layer as the mastodon was predominantly sedge and cattail, while other layers contained that of plants ranging from Canadian buffaloberry, blackberry and wild rose, to willow and alder.^[12]
Gustafson continued to excavate at the site for eight years, finding the partial remains of two more mastodons. Though stone tools and artifacts of bone were found, Gustafson failed to find evidence of an encampment by the people theorized to have butchered the mastodons.^[13]
Prior to the excavation at the Manis site, which was dated to around 12,000 years old,^[14] archaeological sites west of the Cascade Range considered to be "early" were aged between 9,000 and 6,000 years old.<sup>[15]

end partial quote from:</sup>

1. Manis Mastodon Site - Wikipedia, the free...

   en.wikipedia.org/wiki/Manis_Mastodon_Site

   The Manis Mastodon site ... The pollen found in ... The Manis Mastodon Site remains the oldest archaeological site on the Olympic Peninsula in Washington State and ...
   
   The other interesting thing about Dolmens is that they are all over the world and the most of them in one place is in Korea where there are at least 1000. So, obviously there was worldwide communication (in regard to culture or religion) possibly through sailing or camel trains or horse trains or something when all these dolmens were built mostly
   
   between 4000 and 3000 BC or (BCE).