The detection of small forces using singly clamped cantilevers is a fundamental feature in ultrasensitive versions of scanning probe force microscopy. In these technologies, silicon-based nanomechanical devices continue to be the most widespread high-performance nanomechanical sensors for their availability, ease of fabrication, inherently low mechanical dissipation, and good control of surface-induced mechanical dissipation. Here, we develop a robust method to batch fabricate extreme-aspect-ratio (103), singly clamped scanning nanowire mechanical resonators from plain bulk silicon wafers using standard photolithography. We discuss the superior performance and additional versatility of the approach beyond what can be achieved using the established silicon on insulator technology.