The Motus Wildlife Tracking System (Motus) network is increasingly used to track movements of migratory species including monarch butterflies. In addition to their long-distance migraoty movements, western monarchs are also known to move between overwintering sites. We piloted the use of Lotek dataloggers to track lightweight Motus tags attached to western monarchs to examine inter-site movements and butterfly response to tagging. We placed receivers adjacent to and between two overwintering sites that were 1.34 miles apart at Montana de Oro State Park in central California. We affixed Lotek nanopin Motus tags to 18 monarchs using superglue. We determined only one centrally located receiver tower was necessary to pick up between grove movements, therefore only report the data from this location. We collected over 19,000 detections during a 7-day trial. Thirteen monarchs (72%) moved between the sites, though the majority of detections for a given individual were at the site where they were tagged. Four monarchs either departed the study area or their tags stopped working. The datalogger batteries used to power the towers lost power after 7 days, well before the tag batteries died. Using a handheld device, we dected one tag 81 days after deployment, well beyond the tag's predicted 15 day lifespan. Motus tags display promise as a tool that can improve understanding of monarch movements during the overwintering period, a critical part of their multi-generational life cycle.