The following podcasts were created for use during a professional development workshop on teaching geology for in-service, secondary-level science teachers.
The three podcasts cover: podcast 1 - an introduction to the site, with safety considerations for listening to podcasts in the field, podcast 2 - prominent theories of development of Grand Canyon, and podcast 3 - current depositional processes that create rapids in Grand Canyon and make the canyon appear as it does today.

Introduction
1-Introduction_Toroweap110326.mp3

Podcast 1
This podcast is designed for use looking upstream into Grand Canyon, in the location of the student in the image on page 8 of the "Podcasts Amplify Learning in the Field" article of the April, 2011 volume of In The Trenches.
2-Podcast_1-Toroweap110326.mp3

Podcast 2
This podcast is designed for use looking downstream into Grand Canyon at the southern end of the Toroweap Overlook, where Lava Falls can be clearly seen. This is podcast that students are listening to in the cover image of the April, 2011 volume of In The Trenches.
3-Podcast_2-Toroweap110326.mp3