Upper and Lower Table Rock tower over the Rogue River valley, and their unique geological features shape how water moves and ponds at the top of the landforms. Their namesake accurately conveys the flat top you reach after a few miles of climbing. This unique landscape was catalyzed by volcanic activity nearly 7 million years ago when a shield volcano (near present-day Lost Creek Lake) erupted and filled the river canyon with molten basalt. The lava filled the Rogue River and its tributaries. Over the next several millennia, the Rogue River established a new path, slowly carving through the underlying, softer rocks while the harder basalt remained, resulting in the horseshoe-shaped, flat-topped mesas still standing today. Since the volcanic eruption, the valley has eroded about 600-700 ft down in an excellent example of inverted topography. Imagine a winding river, meandering through- that’s the shape of the Table Rocks. These horseshoe shapes were once the curves of a river. It’s a fascinating geologic feat, and it provides an incredibly diverse and beautiful habitat.
Not only are these hikes known for their wildflower sightings, but these communities are also known for being biologically unique. Several plants growing on the Table Rocks are near the northern extent of their range and are rare to see in Oregon. There are also species that only appear in this area, ignoring the surrounding parts of the valley. Look out for these plants that are endemic (species restricted to a narrow geographic distribution) and worth seeking out!
Southern Oregon buttercup (Ranunculus austro-oregonus)
~ Bloom time: Early March - Mid-May
Henderson’s fawn lily (Erythronium hendersonii)
~ Bloom time: Early March - Early June
The dwarf woolly meadowfoam (Limnanthes floccose ssp. pumila)- occurring only on the tops of the two Table Rocks and nowhere else in the world!
~ Bloom time: March - April
Images through iNaturalist (from left to right); Jared Dodson Southern Oregon Buttercup, Chloe & Trevor Van Loon Henderson’s Fawn Lily, and Dayne Galash Dwarf Woolly Meadowfoam
Let’s jump into vernal pools- figuratively!
These shallow pools of water are present only in the winter and spring when snowmelt and rain are at their peak. They are actually considered a type of seasonal wetland. Wandering atop the Table Rocks in the spring almost feels like a Scottish Highlands adventure, but it’s very important to wander on the path. This habitat type is incredibly rare, so we need to make sure the pools are protected as the species that use them have very limited options.
For example, the fairy shrimp (Branchinecta lynchi), federally listed as threatened, inhabit these formed vernal pools. Fertilized eggs are either dropped to the pool bottom or remain in the brood sac until the mother dies and sinks to the bottom of the pool. When the pool dries out, so do the eggs– they become “cysts” which have protective coverings to help them survive multiple years until environmental conditions are acceptable. They remain in the dry pool bed until hatching begins in response to rains and the return of water in the vernal pools. It’s a quick life once they hatch, living only 90 days, on average.
There are two amphibians that call the Table Rocks home. The western toad (Anaxyrus boreas) and the Pacific treefrog (Pseudacris regilla) lay their eggs in the vernal pools and move to the surrounding woodlands once they complete metamorphosis. These species tend to be nocturnal, hiding out in moist woods and waiting for the cool nights to begin their chorus. Amphibian populations are in steep decline nationwide, so protecting these breeding habitats are crucial for their survival.
This is not an exhaustive list of wildlife on the Table Rocks. This unique area is home to many mammals, reptiles, birds, and invertebrates. Keep your eyes peeled for them, and make sure to leave them wild. The best way you can help is by staying on the path; this simple effort protects sensitive vegetation, eggs/cysts, and other small living things hiding in the wet grasses and ponds.
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