Tucson has two named rivers that skirt the city and join as one in the northwest corner. The northern edge of town finds the Rillito River while the Santa Cruz River boarders the western flank of the city. Although both rivers are deemed navigable, by the EPA, the term navigation losses some of its meaning in this assertion. All rivers in this basin and most Arizona basins are dry most of the time. Only the discharge of a sewage treatment facility and the rare thunderstorm add moisture to the otherwise dry sandy riverbeds of the Rillito and the Santa Cruz Rivers.
This bleak description belies the unique nature of these two city corridors. They travel through highly urbanized sections of Tucson coming within a half mile of center city. They also contain an observable sample of the Sonoran wildlife, such as javelinas, coyotes and bobcats, normally seen in the mountain ranges surrounding the city.
These rivers now (as of August, 2011) have paved paths along their banks that join together at their confluence. The Santa Cruz Linear Park Path and the Rillito River Park Path can now be enjoyed together for an extended walk or bicycle ride. Recently completed bridges spanning numerous washes and path extensions make this possible. This is part of a plan to encircle the city with a paved multi-use path for walking, bicycling and horse-back riding.
Here are some pictures of the Santa Cruz River and its path:
http://www.flickr.com/photos/lasertrimguy/sets/72157622335496047/detail/
http://www.flickr.com/groups/santacruzrivercanoeclub/pool/ read more