The　stalagmite　MC01　was　recovered　from　Macal　Chasm　cave　on　the　Vaca　Plateau　of　Belize　in　1995,　and　an　initial　paleoclimate　interpretation　was　published　in　2007.　Additional　uranium-thorium　ages　have　extended　the　paleoenvironmental　record　back　from　3250　to　5250　cal　yr　BP,　and　the　stable　isotope　(delta　O-18　and　delta　C-13)　record　is　dramatically　improved　by　660　new　values.　A　series　of　major　dry　events　(MDEs)　evident　in　stable　isotopes,　ultraviolet-stimulated　luminescence,　and　petrography　began-3100　cal　yr　BP,　and　the　initiation　of　these　events　coincides　with　an　increase　in　El　Nino　dominance　and　southern　shift　in　the　Intertropical　Convergence　Zone.　Three　MDEs,　centered　at　1750　cal　yr　BP　(200　CE),　1100　cal　yr　BP　(850　CE),　and　850　cal　yr　BP　(1100　CE)　and　found　in　other　regional　climate　records,　coincide　with　Maya　sociopolitical　changes.　Residuals　from　regression　of　delta　C-13　versus　8180　are　interpreted　as　a　proxy　for　maize　cultivation　and　land　clearing,　with　residual　values　gradually　increasing　at　the　start　of　Preclassic　Period　settlement　(3950　cal　yr　BP/2000　BCE),　peaking　after　2250　cal　yr　BP　(300　BCE)　during　major　Maya　development　in　the　Late　Preclassic　and　Classic　Periods,　and　dropping　to　pre-Preclassic　values　after　regional　land　abandonment　(similar　to　850　cal　yr　BP/1100　CE).　Regional　Maya　population　growth　and　cultural　expansion　may　have　been　aided　by　abnormally　low　precipitation　variability,　as　stable　isotope　variability　suggests　the　Late　Preclassic　through　the　Late　Classic　was　the　most　stable　precipitation　regime　of　the　past　4000　years.　This　additional　research　on　MCO1　complements　other　regional　paleoenvironmental　records　that　suggest　that　MDEs　coincided　with　disruptions　in　Maya　society　from　the　Preclassic　through　the　Postclassic　Periods.　Although　it　is　clear　that　not　all　significant　sociopolitical　changes　can　be　attributed　to　the　MDEs,　these　events　likely　played　an　antagonistic　role　in　social　stability.　(C)　2016　Elsevier　B.V.　All　rights　reserved.