Between Pachón and Refugio Cave (22°34'28.50"N, 99°01'30.74"W), there is a deep fossil canyon. This canyon may be a barrier for active water connection between the two caves. Distance between Refugio and Pachón caves is 4.5 km.

 
 
  Part of: Espinasa L, Pech A (2023) Biogeographical affinities of the aquatic community of Refugio Cave, a newly discovered Astyanax cave. Subterranean Biology 46: 77-86. https://doi.org/10.3897/subtbiol.46.102043