Lake Rosannah (formerly known as Mud Lake) is protected by surrounding conservation lands and land managed for conservation purposes. A short trail accesses the south end of the lake from Allen Canyon Road.
When I last visited beavers had fallen a tree across the trail. No worries though. I expect the beavers will have the tree removed within a few days.
This lake is where I have often seen flocks of swans. It is quite a site to see when a flock that has been resting on the lake takes to wing. Even from the far side of the lake they are impressive.
The lake is about 3/10ths of a mile from the road. About a half mile from the road there is a nice spot to stop and enjoy the lake. Beyond this point, the trail dwindles to a narrow path, which could be followed some distance further along the shoreline.
The area near the road, where the trail to the lake is located, is owned by the Columbia Land Trust. The rest of the land surrounding the lake is owned by Plas Newdd Farm, is managed for natural resource conservation and closed to public access.