Long range, battery powered, wireless environmental sensor interface devices that can be connected to a plurality of sensors and wirelessly communicate the sensor readings back to a central collection device or Internet terminal. Instead or additionally, sensors can be integrated with the device for added efficiency. The devices incorporate a rugged enclosure and an internal power supply that allows them to be placed in harsh environmental conditions and operate for multiple years without maintenance due to unique power-saving design features. The RF circuitry is specially optimized for long-range outdoor communications of small quantities of data. Line-of-sight communication range of several miles is possible with this device. Various embodiments are disclosed.