Planning to go looking for old lookout sites when we're allowed to go out adventuring again. I am trying to pinpoint the location of the old Hillockburn Lookout. Looking at the 1935 Mt. Hood National Forest map, it looks like there was a Hillockburn Cabin (maybe in the vicinity of the spring?), and the lookout was further south. This site puts it on a peak at 2,379' just beyond the spring and I'm wondering if anyone can verify that.
Here's a trip report from Rob that was a little north of that 2,379' location: https://www.robshikingdiary.com/wp/2012/06/2_4_2012___upper_gipper_trail/
It looks like that area where the lookout was supposed to be didn't get burned during the 36 Pit fire.
I'd be interested to know if you find anything.
We road hiked and bushwhacked to Hillockburn Spring. What a strange spot, with that concrete containment pond. We continued up the road to try and reach the old lookout site, but brush and downed trees forced us to turn back. While the 36 Pit fire did burn along that road, it didn't get as far as the lookout site. Perhaps if it did the site might actually be reachable! Don't know for sure, but it might actually be easier to go cross-country through the forest uphill from Road 45.
Photos (past and present) and maps here.