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The objective of this study was to develop a low-cost, automatic and continuous Herd Activity and Welfare Kit (HAWK). The operational goal for the GPS HAWK was to collect GPS positions and analog sensor data at a user-specified sampling frequency and store it in a secure format. The GPS HAWK uses a Garmin 12-channel, WAAS corrected, low-power GPS receiver with <3 m accuracy. The microcontroller-based system is equipped with six (0-5V single-ended, 10-bit resolution) analog to digital (A/D) conversion channels as well as 16 general purpose I/O pins that can be configured for digital operations or serial communication. Data is stored to an EEPROM device and offloaded daily to a 32MB Compact Flash memory card. Power is supplied using a 6VDC, 7.2Ah sealed lead acid battery. The GPS HAWK was enclosed in a weatherproof enclosure and mounted above the shoulders to provide better satellite visibility to the receiver and to prevent contact with concrete feed bunks in confined animal feeding studies.