• pictures, courtesy of participant Simon Perkins

2001 Green River Trip

• diary, courtesy of participant Jason Lennane

The upper Delores River in SW Colorado is a favorite trip for Tech geology students in the spring. Here we are entering Snaggletooth rapid, a quarter mile of technical white- water rafting. Like most rapids in the Colorado River system, Snaggletooth is caused by boulders dumped into the main channel of the river by a debris flow coming down a tributary canyon.

A morning lecture by Dr. David Johnson on the banks of the Yampa River in NW Colorado. At this point, the Yampa cuts through a thick section of eolian sandstones of Pennsylvanian age (the Weber Sandstone). Numerous stops are made along the river to discuss the geology, many of which involve hikes up tributary canyons.

A Tech raft carefully lines up to run Funnel falls, one of the numerous rapids in Westwater Canyon on the Colorado River east of Moab, Utah. In this canyon, Mesozoic redbeds rest unconformably on Precambrian basement (the latter shown in the photo) where the Colorado River has cut a spectacular gorge through the Uncompahgre Uplift, a major uplift of the Ancestral Rockies.

Here Dr. Kent Condie and three students, who are carefully examining a major hydraulic wave on the front of the boat, enter Souce rapid on the Rio Grande River near Taos, New Mexico. This rapid, like many others in the upper Rio Grande gorge, is formed by rocks that have tumbled down the canyon walls into the river.

Tech students on a geohike in the spectacular Goosenecks of the San Juan River in SE Utah. In this area the San Juan River is superimposed on the Monument Uplift where it cuts down to the Pennsylvanian Honaker Trail Formation. Several reefs in this marine limestone are exposed in cross section on the canyon walls, giving us an excellent opportunity to see reef fossils in situ.

Another interesting attraction in the canyons of the Colorado Plateau in SE Utah are petroglyphs and Anasazi Indian ruins. Here a student examines well preserved petroglyphs and rock varnish on the Navajo Sandstone along the San Juan River.

Dinner time is one of the most popular events on our river trips. Here the food committee is preparing a Mexican enchilada casserole, with all the trimmings, including garlic bread, tossed green salad, and dessert.

Steve Ralser has a good collection of river-trip photos.