An intermittent tributary to the (also intermittent) Moapa River, which flows into the Virgin River, now Lake Mead--at least when the water is high! This part of Nevada is thus part of the Colorado River drainage, not the Great Basin.
This valley also contains the main line of the Union Pacific Railroad between Los Angeles and Salt Lake City. Las Vegas owes its start as a city to the construction of this line (then called the San Pedro & Salt Lake, IIRC) in the mid 19-aughts. Lot auctions were held at what's now the intersection of Fremont and Main Streets in 1905. Vegas celebrated this as its centennial in 2005.
With the winter runoff, we decided that this ford was a little iffy even with the 4x4!