HikeArizona.COM

The second edition authors are Stephen J. Reynolds and Julia K Johnson have done a great job of presenting the Roadside Geology of Arizona's roads. Well illustrated with diagrams, graphs and pictures. Also included is a chapter or rocks and the geological history of Arizona. Next time you are on AZ 87 and in stopped traffic near Mile Post 205 Someone asks you look to the West on the ridge top you think that's a Indian ruin ? You can reply no that's a Proterozoic granite cut by a ridge top dike.

Nighthiker wrote: ↑Feb 23 2026 6:22 pm The second edition authors are Stephen J. Reynolds and Julia K Johnson have done a great job of presenting the Roadside Geology of Arizona's roads. Well illustrated with diagrams,grape and pictures. Also included is a chapter or rocks and the geological history of Arizona. Next time you are on AZ 87 and in stopped traffic near Mile Post 205 Someone asks you look to the West on the ridge top you think that's a Indian ruin ? You can reply no that's a Process pic granite cut by a ridge top dike.

Great and long overdue! Has anyone compared it to the first edition yet? One area I hoped for new information on the Tucson area. The first edition authors had little explanation for how the Tucson area evolved to its current state, especially regarding the number and placement of metamorphic core complex ranges, noting a general lack of consensus on that topic. I've been waiting ages for that gap to get filled in.

@Nighthiker
Thanks for posting this! I just submitted a materials request to the Flagstaff library to purchase it. Hope they do.
[EDIT: I already received an email that they will purchase the book!!]

Does include a chapter on SE Arizona roads including I10 Tucson to New Mexico, I 19, AZ 77, 79, AZ 80, 82, 83, 86 and the Catalina Highway.

@Nighthiker
Are there additional roads featured that weren't in first edition?

Nighthiker wrote: ↑Feb 24 2026 10:52 am Does include a chapter on SE Arizona roads including I10 Tucson to New Mexico, I 19, AZ 77, 79, AZ 80, 82, 83, 86 and the Catalina Highway.

Hmm, maybe there's more discussion of the Jemez Lineament.

Have not noted it, I was wondering about if there is Peridot in the Springerville Volcanic Field.

@Nighthiker
I don't know but I can ask around. I never hear about people going rock-hounding around here. I think if there were semi-precious stones I would have heard about it at some point.

[Edit] I Googled it and it said that it is found on the San Carlos reservation but not in the Springerville volcanic field.

azbackpackr wrote: ↑Feb 24 2026 4:32 pm [Edit] I Googled it and it said that it is found on the San Carlos reservation but not in the Springerville volcanic field.

And if you're unlucky, you'll find asbestos instead (or at least in addition).

big_load wrote:you'll find asbestos instead

@big_load
Only if I'm looking. I don't seem to have caught the rockhounding bug. I have a friend out in Golden Shores/Topock who is an avid rock hunter, makes jewelry, etc. For myself, I don't want to collect more material things, (unless they fall into the category of bike/hike/kayak/musician gear, haha!)

@Nighthiker
This is great news! I’ve seen updates published recently for other states and was hoping Arizona would be updated, too.