The 2021 Marshall Fire displaced thousands across Boulder County, yet a new arXiv preprint (not yet peer-reviewed) reveals that residents did not scatter into isolation. Instead, their daily encounter networks contracted sharply while tightening around people most like themselves. Using anonymized mobile location data to build temporal co-presence graphs at third places, researchers documented a 48% drop in mean weighted degree. Two counterfactual simulations—one random, one based on evacuation propensity—both predicted even steeper losses, showing that actual behavior preserved more ties than displacement alone would allow. This residual connectivity concentrated in bonding links between sociodemographically similar individuals; bridging ties frayed faster. Third places emerged as literal anchors, their repeated use sustaining the surviving edges. The study’s mobility-derived method captures repeated opportunities rather than self-reported support, but lacks direct measures of emotional closeness or long-term recovery outcomes and draws from a single wildfire event. Comparable patterns appear after Hurricane Katrina, where Daniel Aldrich’s fieldwork showed rapid reversion to tight kinship and neighborhood circles for immediate aid, and in post-2011 Tohoku analyses where bridging capital proved fragile under sudden spatial rupture. These cases suggest the Marshall Fire findings are not idiosyncratic but reflect a recurring post-disaster logic: when daily geography collapses, people double down on the circles they already trust most, reshaping support networks in ways that feel immediate and personal to anyone who has watched a familiar landscape burn.