They area said to be on the east side and north of there near the railroad berm. They are very difficult to access from land, I recommend taking a waverunner or some such to get to them.
We were at the Great Salt Lake about 4 weeks ago, and due to drought conditions, 99% of the mud flats appear to be dry. One of the folks in our group had a drone, which he was very quickly asked to land and put away. We didn't realize, because we never read the fine print on the map, but flying drones anywhere around, or near, the Great Salt Lake requires a permit. But anyway, we did get some wonderful pictures before we had to land it, and just about everything except the lake itself looked bone dry. The water's edge has receded about 200 yards since we were last there 15 plus years ago due to the area being in a drought for the past 5 years or so..