Realizing the vision of ubiquitous battery-free sensing has proven to be challenging, mainly due to the practical energy and range limitations of current wireless communication systems. To address this, we design the first wide-area and scalable backscatter network with multiple receivers (RX) and transmitters (TX) base units to communicate with battery-free sensor nodes. Our system circumvents the inherent limitations of backscatter systems -including the limited coverage area, frequency-dependent operability, and sensor node limitations in handling network tasks- by introducing several coordination techniques between the base units starting from a single RX-TX pair to networks with many RX and TX units.