Inland parts of Oregon and Washington, as well as Idaho, have experienced a strange, murky rain today that contains what seems to be volcanic ash, though ash from which volcano isn't completely clear. Experts said they are checking out several possible explanations including a recent volcanic eruption in Mexico and one in Russia. The weather service said the rainstorm may have passed through some dust or volcanic ash as it moved west. Walla Walla County's emergency management staff posted a statement on its Facebook page that the ash is likely from Volcano Shiveluch in Kamchatka Krai, Russia, some 3,000 miles away. Volcano Shiveluch spewed an ash plume about 22,000 feet high in late January, the statement said.... CNN meteorologist Derek Van Dam, meanwhile, pointed to an eruption Wednesday of a volcano in southwestern Colima, Mexico, as another potential source of the dirty rain. That volcano is more than 2,000 miles away from the region. Time points out that other theories include leftover ash from last year’s wildfires in Oregon in Idaho.