over the 2004 peak visitor season, a covert observational study was conducted at st. lawrence islands national park, ontario, canada to assess the extent of social trail use on two islands. the study examined the effectiveness of message text, and location on signs aimed at reducing the amount of social trail use by visitors. attribution and species-at-risk messages were more effective than simple messages at eliciting desired behaviours. furthermore, when signs were posted at specific locations of interest, social trail use was reduced significantly compared to no messages, or messages located at points of entry alone. attribution messages may lead to environmental attitudes becoming accessible. gender and age of visitor also influenced social trial behaviour.