Using a computational genetic approach, we have identified 22 novel methylation guide snoRNAs in Saccharomyces cerevisiae, all of which are expressed, and all but one of which has been functionally verified by gene disruption. We have also identified and verified 12 of the remaining 13 unmapped ribose methyl sites in S. cerevisiae ribosomal RNA based on strong snoRNA predictions. Four of these new sites were recently inferred from existing C/D box snoRNAs and confirmed independently by another research group [Cavaille & Bachellerie, 1998].