Hircine's realm is not all forest, however. It has open plains and vast canyons. Hircine, being the god of the hunt, would surely have different enviorments to hunt. We already saw mazes in Bloodmoon, though in Nirn, it was an extension of his realm on Tamriel. I am sure there are jungles and maybe even an open tundra. Who knows? We have seen open plains and a large forest. I am also sure there can be people living in Hircine's realm. We saw from Infernal City that he has Lyanthropic nords(werebears) hunting any newcoming mortal, we can expect a hunter's camp or cottage in lore regarding the realm. They must have a place to live if they hunt during the day and at night too(If I recall, they stepped aside when Hircine came along. In reverance to the Prince, they stood by as Hircine and his werewolves attacked the protagonists.) The river was easily speculated to be blood because it was red. And also, Hircine's hunting grounds only has a single silver moon that matched earth. The sun is also bright red. If they add it into the game, which I doubt(After Shivering Isles, Bethesda said they are doing Fallout-like DLC.), I expect to see many interesting things. Not to mention the indiginous life such as those weird cattle animals that grazed on the fields.
It almost sounds like America before the mass arrival of Europeans to the continent...I would expect the weird cattle to resemble something much like the http://en.wikipedia.org/wiki/Bison...I do so love the werewolf http://www.gamesas.com/index.php?/topic/1202629-if-werewolves-are-approved/ on this site...