The dataset presents a snapshot of crowdsourcing data collected on iNaturalist.org and identified by a group of professional mycologists during a revision of crowdsourcing data project (https://sibmyco.org/collections/inaturalist-revision/). The resulted data were exported from iNaturalist.org, analysed and described in a related publication (Filippova et al., 2022).A regional mycological club was established in 2018, encouraging its members to contribute observations of fungi to iNaturalist.org (https://www.inaturalist.org/projects/fungi-and-myxomycetes-in-northern-west-siberia). A total of about 15K observations of fungi and myxomycetes were uploaded so far, by about 200 observers, from three administrative regions (Yamalo-Nenets Autonomous Okrug, Khanty-Mansi Autonomous Okrug and Tyumen Region).The goal of the work presented in this study consisted in a collaborative effort of professional mycologists who were invited to help with the identification of these observations and analyze the accumulated data. As the result, all observations were reviewed by at least one expert. About a half of all observations have been identified reliably to the species level and received Research Grade status. Of those, 197 records of 92 species represented finds of taxa new to their respective regions; such finds are listed in the Attachment with brief commentaries; 876 records of 53 species of different protection status provide important data for conservation programs.The remaining half of the observations consists of records that remained under-identified for various reasons: poor quality photographs, complex taxa (impossible to identify without microscopic or molecular study), or lack of experts in a particular taxonomic group.Despite that the half of presented records already published through GBIF in "iNaturalist Research-grade Observations" dataset (https://doi.org/10.15468/ab3s5x), we decided to publish a dataset which includes all observations updated by the date of paper publishing and preserved at this state for archiving purposes. The dataset is made with the assumed pros and contras in mind:Pros: 1) We want to preserve the results of revision work with iNaturalist-based observations in a stable archive. On the contraty, the observations data published on iNaturalist.org are always revised and updated; 2) We aim to publish raw (source) data for the revision paper analyses in a single FAIR archive; 3) We want all records published on iNaturalist.org to be used in further study of fungi in the region and globally, including "Needs ID" status observations; provided that these records were reviewed by professional mycologists and received at least two expert opinions; 4) The resulting dataset was augmented with several fields to add information about regional novelties and identification remarks.Contras: 1) Duplication of records in two dataset (iNaturalist and ours), which nevertheless could be solved by GBIF duplicates search algorithm.