There are two types of theories of RC extraposition in the literature: movement theories (Baltin 1981, 1983; Ross 1967) and non-movement theories (Chomsky 1973; Culicover and Rochemont 1990; Fox and Johnson 2016; Fox and Nissenbaum 1999; Hunter and Frank 2014). One classic diagnostic for movement is the presence of island effects. Culicover and Rochemont (1990) observe that English RC extraposition can escape Subject islands, suggesting that non-movement theories may be correct for English. However, this observation does not exclude movement theories entirely. It is well-established that different types of Ā-movement can be differently sensitive to island effects, even in the same language. It is possible then that RC extraposition may be due to movement, but is able to escape some syntactic islands and not others. A more exhaustive test of the full range of island types is required to eliminate this possibility. However, in English (and many other languages), this is not possible because of the Late Closure processing strategy, which causes extraposed items to be interpreted as part of the most deeply embedded clause (i.e., within post-verbal islands) (Frazier 1978). Crucially, Russian employs an Early Closure strategy (Sekerina 2003), which allows the extraposed clause to be interpreted outside of the island with appropriate syntactic cues. Therefore, here we report a series of 12 experiments comparing *wh*-movement (as a baseline comparison) and RC extraposition for a wider set of six island types in Russian: Adjunct, Noun Complement, WH, and three types of Subject islands (transitive, unergative, and unaccusative). We find that both *wh*-movement and RC extraposition are sensitive to island effects, suggesting both dependencies are created by syntactic movement; though, we also find that the set of islands are partially distinct in ways that suggest potentially interesting syntactic consequences.