The Barbie Fan: A pathologically perfect Nevada alluvial fan
The state of Nevada has more fans than Las Vegas has foreclosed properties (that's a lot). This particular fan was termed the 'Barbie' fan by my co-author and UNLV colleague Brenda Buck. The name is appropriate because the shape is almost too ideal. We mapped most of the Barbie fan as part of the Ivanpah Valley Mapping Project (the Ivanpah-viathan).
The fan does have an ideal fan shape. It is also comprised of an elaborate assemblage of Quaternary alluvial surfaces of a broad range of ages, thus further substantiating its Barbie-ness. (see, for example, the paper about the Cedar Creek alluvial fan in Montana...this paper was a field camp staple when I used to run a course on fans in eastern Nevada). Here are links showing different characterizations of the geology of the Barbie Fan:
The Barbie fan is fed by a drainage that cuts right through the Lucy Gray Mountains. It obliquely straddles the border with California, and its outermost point creates a divide between two dry lakes where the fan grazes the southern extremity of the Spring Mountains. The 'lake' to the north (Roach Lake) is entirely in Nevada and the 'lake' to the south (Ivanpah Lake) is about 99.9% in California. The divide now hosts a casino and outlet mall complex (and a roller coaster....Nevada, remember?). The border runs through the parking lot.
Take a look at the recent drainage courses on the fan and appreciate how a relatively small change in the position of a major distributary channel could convey a flood entirely to either state, or both. A dilemma for water lawyers, possibly. Certainly a potential dilemma for the major airport that has been planned (now on hold for economic reasons) to span the entirety of Roach Lake (yes, that is right, a major airport...Nevada, remember?). Note that Las Vegas is not too far away...just up I-15 about 35 miles. http://www.flashearth.com/?lat=35.59174&lon=-115.363046&z=10.7&r=0&src=msa