This image is signed "O.T. Frasch," but in writing not typical of his. Perhaps an assistant was responsible for lettering this and other images with the same style of writing.
Multiple sources including the Shelton Mason County Journal identify the fourth man from the left as President Theodore Roosevelt, on one of his multiple visits to Lake Cushman:
Apparently this photo was taken during President Roosevelt's 1909 visit, about the time he designated land for a national monument that is now Olympic National Park.
Oscar Ahl, the owner of the boat used to ferry passengers across the lake, is standing outside the cabin just to the left of President Roosevelt. We don't know the names of anyone else in the photo, though the woman at the far right resembles Otto's wife Mary.
This image is one of a number of O.T. Frasch photos used in Dan Warter's video "The Search for the Antlers Hotel." The site of the hotel, featured in several O.T. Frasch photos of Lake Cushman, is now underwater after the level of the lake was raised by a hydroelectric dam.
There is another Image 283 (283 - South Entrance A.Y.P.E. (Built of Totem Poles)) showing an entrance to the Alaska Yukon Pacific Exposition. Perhaps Otto reused the image number because no one would be interested in an A.Y.P.E. card after the exposition ended.