This volume, Spirit & Reason: The Vine Deloria, Jr., Reader is not, however, his best work. Rather, this is a collection of bits and pieces on various topics, some being excerpts from his various (a dozen plus editorial projects) books, others being articles originally published in assorted magazines and journals, and suffers from the realities of that structure. Also, Deloria is most powerful when writing about subjects like religion, politics, and historical realities. While these subjects are included in Spirit & Reason, they are intermixed with other materials that one feels are not his strong suit.
I will admit that some of the parts that I felt were "stretching" could have just been my own reaction to points of view that I find based on highly unlikely premises (such as the suggestion that certain types of dinosaurs were co-existing with native tribes in North America within historical times), but that could simply be my inability to detach from particular archaeological or anthropological orthodoxies. There were also some bits where I had the reaction that he was over-stating certain elements for the specific audience for which a given article was initially written, but those could likewise be simply my biases conflicting with his reality.
The book is structured in five "thematic" segments, Philosophy, Social Science, Education, Indians, and Religion, with a good deal of variety of subjects within each of these. Again, the "quality" rises and falls chapter to chapter, but that is to be expected in a collection of this nature. Personally, I would not recommend this for an introduction to Deloria, but would suggest if one has not read him, to start with God Is Red, which is a remarkable book.
This does still appear to be in print (in the paperback edition), so could be found via "brick & mortar" channels, but the Amazon new/used vendors currently have "new" copies available fro as little as $5.75 (on an $18.95 cover price book), so if you were wanting to add it to your library, I'd say go with that!