Marching with heavy load is a large component of military training and standard operations. The rate of the march may approach or surpass the velocity at which warfighters would prefer to run, however, they are strongly encouraged to maintain a walking gait. Previous research has observed gender differences in biomechanics and prevalence of injury during load carriage. The primary purpose of this study was to investigate the effects of load carriage magnitude on lower limb kinematics, kinetics, and spatiotemporal metrics at velocities around the gait transition point (GTP) in female subjects. As a secondary aim, the effects of load carriage on coordination variability were assessed. Twelve recreationally active females (24.75 ± 2.26 years) completed three testing sessions. 3D biomechanics were captured via 12 infrared cameras (Vicon Motion Systems, Oxford, UK) and a Bertec fully instrumented treadmill (Bertec Corporation, Columbus, Ohio). Prior to data collection, GTP velocity was determined by averaging 3 walk-to-run trials for each load condition. Experimental trials were conducted at body weight (BW), and with loads; +25%BW, and +45%BW. For each load condition, participants walked (WK), ran (RN) or force-marched (FM) at velocities around their GTP velocity. Kinematic data were acquired at 100Hz and kinetic data were acquired at 1000Hz. Repeated measures analysis of variance were conducted to examine the effect of load and marching velocity on sagittal plane kinematics, kinetics, and spatiotemporal metrics. Results showed that increases in load carriage magnitude increased stride width, stance time, and double support time and decreased stride length and flight time. Knee flexion and ankle dorsiflexion at mid-stance increased with increases in load. Overall, joints were more flexed at each gait event during running. Lower extremity relative joint moments decreased with increases in load. Hip and knee moments were greater during forced-marching at heel-strike and toe-off. All joint moments were greater during running at mid-stance. Increases in load did not appear to decrease the variability of shank-thigh coupling. Additionally, there was no apparent difference in coordination variability between RN and FM trials. Future studies should investigate the biomechanical differences between trained and untrained males and females.