The purpose of this study was to document the instrument development of maze measures for grades 3-8. Each maze passage contained twelve omitted words that students filled in by choosing the best-fit word from among the provided options. In this technical report, we describe the process of creating, reviewing, and pilot testing the maze measures. We use three analytic approaches for estimating item difficulty of the test items sampled. The findings of content review and data analysis provide evidence supporting this instrument development process. We conclude that these maze measures are a viable reading comprehension assessment for students in grades 3-8, based on the convergence of evidence. Appended are: (1) GOMs Maze Measure Internal Review; and (2) Directions for Administration. (Contains 53 tables.)