Bangs's mountain squirrel (Syntheosciurus brochus) is a poorly known species of tree squirrel, that only lives in Costa Rica and Panama.

One of its habitats is at the summit of the Poás Volcano in Costa Rica, in a Clusia forest that is almost inaccessible to humans.

Because of the shape of its skull and teeth, the species has been separated from the genus of typical tree squirrels, Sciurus, into its own (monotypical) genus Syntheosciurus.

Since then, the species has been studied more in depth, especially by the zoologists N.M.Wells and J.Giacalone, who write that these mountain squirrels are sociable creatures.

These squirrels live in pairs, together with their young, in a tree nest at a height of 6 to 12 metres (20–39 ft).