WOCS. RV Measurements in M35 11 (NGC 2168). In this first paper, we present our RV ob- servations and provide initial results from this survey. Our stellar sample extends to 30 arcminutes in radius from the cluster center (7 pc in projection at a distance of 805 pc or ∼ 4 core radii), and we have selected a region from a V , ( B − V ) CMD (Figure 1) which covers a mass range of 1.6 - 0.8 M ⊙ . We have used the WIYN 3.5m telescope with the Hydra MOS to obtain 5201 spectra of 1144 stars within this stellar sample. From these spec- tra, we derive RV measurements with a precision of 0.5 km s − 1 for narrow-lined stars. The vast majority of the observed stars have multiple measurements, allowing de- termination of cluster membership and identification of spectroscopic binary stars. We detect 360 cluster mem- bers, 55 of which show significant variability in their RV measurements. Binary orbital solutions have been ob- tained for 39 of these RV variables, which we will present in detail in the next paper in this series. Observations of the rest of the RV variables and the remainder of our stellar sample are ongoing. Table 3 provides the first RV membership database for M35 and extends ∼ 1.5 magni- tudes deeper than any previous membership catalogue. After correcting for measurement precision, but not for binaries, we place an upper limit on the RV dispersion of the cluster of 0 . 81 ± 0 . 08 km s − $^{1}$. When we also correct for undetected binaries, we derive a true RV dispersion of 0 . 65 ± 0 . 10 km s − $^{1}$. The WOCS group will continue our survey of M35 in order to derive RV memberships for all stars in our stellar sample and obtain orbital solutions for all binaries with periods less than a few thousand days, as well as some with longer periods. In future papers, we will study the binary population of M35 in detail, providing all orbital solutions and analyzing the binary frequency and dis- tributions of orbital parameters. These data will form essential constraints on the hitherto poorly known initial binary populations used in sophisticated N -body models of open clusters. Using the RV cluster members, we study the spa- tial distribution and velocity dispersion of the single and binary stars. We find their spatial distributions to be indistinguishable. This lack of central concentra- tion for the binaries is consistent with earlier observa- tional studies of stars in M35 as well as with a fully re- laxed dynamical model for the cluster (Mathieu 1983; McNamara & Sekiguchi 1986b). In these studies, mass segregation is seen in higher-mass stars, but diminishes to being undetectable for stars in our observed mass range. The authors would like to express their gratitude to the staff of the WIYN Observatory for their skillful and dedicated work that have allowed us to obtain these ex- cellent spectra. We thank Ata Sarajedini and Ted von Hippel for the acquisition of the Schmidt images, Vera Platais for work on the astrometry and photometry as well as John Bjorkman for early photometry work. We also thank the many undergraduate and graduate stu- dents who have contributed late nights to obtain the spectra for this project. This work was supported by NSF grant AST 0406615 and the Wisconsin Space Grant Consortium. Facilities: WIYN 3.5m REFERENCES Barrado y Navascu´es, D., Deliyannis, C. P., & Stauffer, J. R. 2001, ApJ, 549, 452 Carraro, G., Girardi, L., & Marigo, P. 2002, MNRAS, 332, 705 Cudworth, K. M. 1971, AJ, 76, 475 Dabrowski, J. P., & Beardsley, W. R. 1977, PASP, 89, 225 Duquennoy, A., & Mayor, M. 1991, A&A, 248, 485 Ebbighausen, E. G. 1942, AJ, 50, 1 Geller, A. M., Mathieu, R. D., Harris, H. 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