KwandongAlex and I will do the five km route starting at 10AM on Saturday. It starts at Seorak Park Hotel, near the main Seorak office and more or less two km from the main entrance. I expect we will be joined by the Domestic Blisses.
This evening I found a poster at the apartment lobby for a series of 'marathons' in Gangwond0 (and possibly elsewhere - I didn't study the poster too closely). Sokcho's run, seven km around Youngnang Lake, is also scheduled for this Saturday, starting at 9:00 AM. The poster included a website, but it is just the general one for the Gangwon Ilbo* (the provincial newspaper) and not specifically for the run.
I notice that the run will be held on different days in different cities. Perhaps I can do a similar run next weekend.
I don't know if the Gangwon Ilbo is simply sponsoring a run for health and advertising purposes or if the events are for something else. Both the run and the walking festival carry "Pyeongchang Olympic bid 2018" promotions.
*I am currently using the Windows side of my computer and google's Chrome browser. When I looked at Gangwon Ilbo's website in Chrome, a list buttons for regions appeared right in the middle of the page obscuring much of the text. In Explorer, it is comfortably on the right side.