The flow of knowledge is closely linked to proximity. While extensive works show that long-term geographic proximity affects work behavior, little is known about the effect of short-term colocation, such as conferences. Using participant data at Gordon Research Conferences, we estimate difference-in-differences and instrumental variable models, which show that attendees who have no prior within-conference collaborations are more likely to collaborate with other attendees, and that the researchers who have worked previously with other attendees are more likely to continue their collaborations. We also find that researchers who are junior, are located closer to the conference venue, and have established prior ties to the conference draw more collaborative benefits from temporary colocation across organizations. Thus, going to a conference alters the creation of collaborations.