Multiscale Systematic Conservation Planning Across Nested H3 Grids R package MultiscaleSCP version 0.2.0 Provides tools for multiscale systematic conservation planning using the H3 hierarchical hexagonal grid system (Uber Technologies (2024) <https://h3geo.org>) and the 'prioritizr' package (Hanson et al. (2025) <doi:10.1111/cobi.14376>). Supports the definition and solution of conservation problems across nested H3 resolutions with resolution-specific features, costs, and management attributes, including cross-scale connectivity penalties derived from parent-child relationships. Includes a multiscale minimum-set objective that allows planning units at different resolutions to contribute toward feature representation targets while accounting for overlapping costs and feature amounts across nested planning units. Also includes utilities to evaluate solutions using multiscale-aware diagnostics and to post-process optimization outputs into alternative area-targeted conservation scenarios. Software Depends: R (>= 4.2) Imports: sf, units, terra, raster, dplyr, tibble, Matrix, methods, prioritizr (>= 9.0.1), Rcpp, exactextractr, stats, cli, R6, assertthat, h3jsr, rlang LinkingTo: Rcpp Suggests: highs, knitr, rmarkdown, testthat (>= 3.0.0) Pablo Merlo <pablo.merlo@universityofgalway.ie> Comprehensive R Archive Network (CRAN) Pablo Merlo [aut, cre] (ORCID: <https://orcid.org/0000-0002-0626-4993>), Oisín Callery [aut] (ORCID: <https://orcid.org/0000-0002-3388-0951>), Carlos Tighe [ctb], Anthony Grehan [ctb] MIT + file LICENSE (https://CRAN.R-project.org/package=MultiscaleSCP/LICENSE) 2026-10-14 application/tgz https://CRAN.R-project.org/package=MultiscaleSCP doi:10.32614/CRAN.package.MultiscaleSCP