*Populations KS2S (n = 4) and KS8S (n = 1) had individuals removed due to data missing >20%

Figure Legends

Figure 1. Map of three EPSPS haplotypes in glyphosate-resistant kochia (Bassia scoparia). 1) increased EPSPS copy number, presence of type I and II repeats, MGE ≥ 10 (Central Great Plains); 2) increased EPSPS copy number, no Type I or II, MGE ≥ 10 (Northern Plains); 3) increased EPSPS copy number, no Type I or II, MGE < 10 (Pacific Northwest, some Wyoming). Figure legend created using BioRender.

Figure 2. Population level phylogeny tree in glyphosate-resistant kochia (Bassia scoparia). Forty-four kochia populations are included in this analysis. The neighbor-joining tree is based on Prevosti’s distance. Bootstrap values (%) are shown if >20% and are based on 1000 replicates. Glyphosate-resistant, (R) and -susceptible (S); CGP1, Central Great Plains (green square with diagonal lines); NP2, Northern Plains (yellow square with vertical lines); PNW3, Pacific Northwest (blue square with horizontal lines).

Figure 3. Bayesian clustering analysis (STRUCTURE) in glyphosate-resistant kochia (Bassia scoparia). Assignment of 509 kochia individuals from 44 populations to the K=3 genetic clusters inferred by analysis. Populations are sorted by region (Central Great Plains, Northern Plains, and Pacific Northwest) and alphabetized within region. Each horizontal bar corresponds to a distinct individual and its probability of assignment, q , to each cluster.