|Abstract:||The Merced River in the popular and picturesque
eastern-most part of Yosemite Valley in Yosemite National Park,
California, USA, has been extensively altered since the park was
first conceived in 1864. Historical human trampling of
streambanks has been suggested as the cause of substantial
increases in stream width, and the construction of undersized
stone bridges in the 1920s has been suggested as the major
factor leading to an increase in overbank flooding due to
deposition of bars and islands between the bridges. In response,
the National Park Service at Yosemite National Park (YNP)
requested a study of the hydraulic and geomorphic conditions
affecting the most-heavily influenced part of the river, a
2.4-km reach in eastern Yosemite Valley extending from above the
Tenaya Creek and Merced River confluence to below Housekeeping
Bridge. As part of the study, present-day conditions were
compared to historical conditions and several possible planning
scenarios were investigated, including the remova