Last year I posted a consideration of the “Crook” motif as seen in Lake County, Oregon. 
This simple and distinctive motif appears at times in association with other figures on panel and oft times as a “floating” figure absent any obvious referent. Other than usually facing a water source.
At their most concise, the abstracted form appears as a symbol: a half circle arching upward with a brief extension on one side. Perhaps it is better to not call them “crooks,” or hooks, or any name.
Recently I discovered paper by Bernard M. Jones, Jr , which to added new depth to my thinking about this form. I find his thoughtful investigation of power, or “powerscapes” as he proposes, quite provocative. Most of his examples include associations with anthropomorphs, as do the references I noted in my earlier post. However, forms of the petroglyphs in the northern Great Basin vary wildly and generally depart from any anthro-association: Crook Motif: Expanded
 By Crook or by Hook: Abstract petroglyph motifs in Lake County. Feb 18 2014
 Bernard M. Jones, Jr. 2012. The Shaman's Crook: A Visual Metaphor Numinous Power in Rock Art. In Utah Rock Art Vol XXX, URARA.
Look closely: Two Crooks emerge, with dots and other figures - an old petroglyph as are most of rhe "floating" crooks in Lake County, Oregon