The "south end" of Yuba Lake State Park is everything south of Painted Rocks on the "Yuba Lake" section of the reservoir. This open water area is surrounded by desert, shrubsteppe, and juniper woodlands in the hills to the east and west. A large floodplain where the Sevier River enters the lake on the south end creates various amounts of wetland, mudflats, beaches and otherwise unique habitats depending on the water levels of the lake. Due to its dry surroundings this area is an oasis for waterbirds.
Another under-birded hot spot the south end of Yuba doesn't get a ton of visits from birders. In order to get here you would have to be on the west side of the lake for one reason or another and make an effort to bird the lake as you pass. That being said it looks quite enterprising and could hold some interesting waterbirds especially during migration. The fall might be exceptionally interesting given that this is the south end of the water, and nothing but open desert lies to the south. The current eBird list consists of just a a few species. CANADA GEESE, MALLARD, NORTHERN SHOVELER, and GREEN WINGED TEAL to name a few of the waterfowl. AMERICAN WHITE PELICAN and DOUBLE-CRESTED CORMORANTS for diving birds, and even SANDHILL CRANE. I would image the bird list could potentially look something like Chicken Creek Reservoir if it were birded more often. The surrounding desert is prime for LARK SPARROW, SAGE THRASHER, and of course HORNED LARKS. Once upon a time I remember seeing BURROWING OWLS in the area, and GOLDEN EAGLES hunting on the prairie here. IF you find yourself passing Yuba and have a day to spare, it might be worth exploring this and all the other locations at this unique and isolated state park!
You have to make a concerted effort to reach this campground isolated on the east side of the lake. There are numerous ways to get here, and if you are birding on the the east side of the lake the best route is to drive to the north end of the reservoir and turn right onto Old Botham Road and go east 5.7 miles. Turn right onto Hwy 28 and go 3.4 miles. Everything south of this point on the west side of the road within the state park boundaries is part of this hot spot. Alternatively you could take Hwy 28 all the way from Nephi south to Levan and then continue till you pass the turn off to Painted Rocks--then as mentioned above you are in the south part of the park.