The Ruth McKenzie Table Mountain Preserve (2960 acres) is located between Friant and Prather, on the north side of Auberry Road. The main gate is 3.3 miles uphill from the intersection of Auberry Road and Millerton Road.

The McKenzie Preserve was acquired in trust from The Nature Conservancy in 1998. The property had previously been placed in a trust by its owner, Ruth Bea McKenzie, who wanted it to remain in ranching and open space after her death.The McKenzie Preserve is primarily grassland and oak woodland that slopes upward toward the basalt lava table lands that give the preserve its name.

The preserve includes a significant portion of one of the flat-topped tables that are visible from the road. In spring, rain water collects in the tables low spots, forming vernal pools. Since the basalt is impermeable, these pools hold water for several weeks or months until it eventually evaporates. The pools provide habitat for rare plants and crustaceans that come to life in the presence of the water. When the pools dry up in late spring, these crustaceans become seeds or cysts in order to survive the rest of the year. On the far side of the table formations, out of sight of Auberry Road, the land slopes steeply down to the San Joaquin River. These north-facing slopes sustain an excellent mix of pine forest and chaparral. The preserve also includes a 47-acre parcel along the creek on the south side.