To start, Tanner is the correct name, not Tannen. Tannen is an error made by USFS on their maps and unfortunely they and others using their maps have not corrected it. I saw some beautiful pictures of this area pre-fire. It was once very beautiful but now very damaged by fire. Not as bad as Althouse, still some shade and timber but not much. The little lakes below are lovely.
Basically take FS rd 48 to rd 4812 then 4812-570. I don't think any of this was marked. Guessing all signage burned. On my way to these summits I ran into a guy from Quebec who flagged me down with very little mapping source (an atlas map) and was looking for the Caves. Way off course and low on gas. The road will take you to the TH of the Boundary Trail, no sign but a couple tight spots to park. I had to park down a ways before these pullouts due to vehicles there and fire season I won't park on dry vegetation of course. Hike up the "trail", hard to find and see in some areas due to damage done, up the west ridge. You will get to a grassy area at the top saddle to your left and walking thru that you will see the summit rocks and there is trail to the near top. A bit steep
My doggy refused to do the last bit due to no shade and the heat. She stayed below under a tree while I went just to the AZ. I am sure the view is magnificent from the very top but I had to keep her in sight, the further I went the more manzanita to look over.
de AG7GP
