The tallest mountain in North America, Mount McKinley is situated inside a sharp bend in the right‐lateral Denali fault. This anomalous topography is clearly associated with the complex geometry of the Denali fault, but how this topography evolves in conjunction with the adjacent strike‐slip fault is unknown. To constrain how this fault bend is deforming, the Quaternary fault‐related deformation on the opposite side of the Denali fault from Mount McKinley were documented through combined geologic mapping, active fault characterization, and analysis of background seismicity. My mapping illustrates an east‐west change in faulting style where normal faults occur east of the fault bend and thrust faults predominate to the west. These faults offset glacial outwash terraces and moraines which, with tentative correlations with the regional glacial history, provide fault slip rates that suggest that the Denali fault bend is migrating southwestward. The complex and elevated regional seismicity corroborates the style of faulting associated with the fault bend and provide additional subsurface control on the location of active faults. Seismologic and neotectonic constraints suggest that the maximum compressive stress axis rotates from vertical east of the bend to horizontal and Denali fault‐normal west of the bend.

Strike-slip faults evolve to accommodate more fault slip, resulting in less off-fault deformation. In analog experiments, the measured fault slip to off-fault deformation ratios are similar to those measured in crustal strike-slip systems, such as the San Andreas fault system. Established planar faults have the largest fault slip to off-fault deformation ratio of ~0.98. In systems without a pre-existing fault surface, crustal thickness and basal detachment conditions affect shear zone width and roughness. However, once the applied plate displacement is 1-2 times the crustal thickness, partitioning of deformation between fault slip and off-fault distributed shear is >0.90, regardless of the basal boundary conditions. In addition, at any moment during the evolution of the analog fault system, the ratio of fault slip to off-fault deformation is larger than the cumulative ratio. We also find that the upward and lateral propagation of faults as an active shear zone developing early in the experiments has greater impact on the system’s strike-slip efficiency than later interaction between non-collinear fault segments. For bends with stepover distance of twice the crustal thickness, the fault slip to off-fault deformation ratio increases up to ~0.80-0.90, after applied plate displacement exceeds twice the crustal thickness. Propagation of new oblique-slip faults around sharp restraining bends reduces the overall off-fault deformation within the fault system. In contrast, fault segments within gentle restraining bends continue to slip and the propagation of new oblique-slip faults have less effect on the system’s efficiency than for sharp restraining bends.

Numerical simulations of a 15° restraining bend analog claybox experiment include considering the fault geometry, rheology, and boundary conditions. The numerical models show that a growing fault from an analog experiment propagates at depth rather than at the surface and is exposed in later stages of the experiment, and that the wet kaolin clay from the analog experiment is partially decoupled from the steel plate. The numerical models provide the stresses to predict accurate fault growth from the analog experiment and provide the evolution of external work within the fault system. The external work from the numerical models decrease as faults continue to grow, which agrees with the continuously increasing kinematic efficiency within the analog experiment. Three-dimensional mechanical models are used to simulate the southern San Andreas fault. These models show that incorporating fault interaction, time since last earthquake rupture, and nearby earthquakes affects the stress state along a fault. Absolute shear tractions are calculated by multiplying time since last earthquake rupture with the simulated interseismic stressing rates for each fault strand. From our multi-cycle model, fault interaction affects local normal stressing rates so that the stresses are not relieved in between earthquakes. We provide our absolute shear tractions and scale our multi-cycle normal stressing rates to be near to failure so that dynamic rupture modelers from University of California, Riverside use our results to simulate earthquake propagation for the complex fault region of the San Gorgonio Pass.