GPS Error + Shoulder Pain = Danger
Monday, May 25th, 2026: Burro Mountains, Hikes, Southwest New Mexico.
I was on my way to Tucson for a mini-vacation, and I’d made big gains in my hiking distance and elevation during the past week, so I was temped to skip Sunday’s hike completely. It wouldn’t impact my conditioning and it would give my knee and foot a break – they’re still on the edge of chronic inflammation.
Plus, the high at home – at 6,000 feet – was forecast to be in the low 80s, and the route to Tucson is nearly 2,000 feet lower and ten degrees hotter. I looked hard and couldn’t find a convenient high-elevation hike between here and there.
So I packed, and of course the packing triggered my shoulder pain. And at the last minute, my Calvinist masochism led me to do a partial hike in the mountains south of here. The trail would be exposed, the sky was mostly clear, and it was already warm in town – but it should yield just the right amount of distance and elevation to avoid damaging my joints.
I was drenched in sweat and swarmed by flies within a hundred level yards of the trailhead. Then the trail began climbing, and of course, I’d forgotten how steep it is. Sweat was clogging my head net – I had to keep taking it off, wringing it out, and swabbing my head with one of the bandanas I carry. That all made my shoulder pain worse, but I was running out of pain meds and had to pace myself for the next week.
On the plus side, it’s a rocky landscape – some kind of granite-like igneous boulders and exposed bedrock – and the cactus flowers were gorgeous. And as I climbed higher, little clouds were forming overhead and giving me brief episodes of relief from the heat.
The hike to the peak is a little over 4 miles – I was just aiming for the top of the ridge, the edge of ponderosa pine habitat, for a little over five miles out-and-back. Like everywhere, the small pines here were dying off from drought-induced bark beetle infestation.
On the way down, I stopped for a drink of water – I’d stored my water in the fridge overnight and it was still cool. And a guy in his twenties passed me on his way up. An obvious stranger, he was likely visiting from a distant city for our big event of the year – a music festival – and picked this hike because it’s part of the world-famous national trail. He was dressed very neatly in white t-shirt and crisp REI-style synthetic shorts, and he’d obviously done the climb in this heat without breaking a sweat.
I’ve been plagued by flies during the past month, and have encountered several other hikers like this one who seemed to have no issues – so I have to recognize I produce excessive amounts of sweat. I believe that’s why I’m attracted to warm, arid climates – my body is unusually efficient at cooling itself, even though I do seem to be more heat-sensitive as I get older. Also, I remember vegetarian girlfriends claiming I attract insects because I eat meat – but my younger girlfriends were always looking for an opportunity to make me feel inferior.
On to Tucson – another two and a half hours of mostly interstate highway driving. And the activities of driving an ancient unautomated vehicle – shifting gears, controlling the A/C, managing music on my iPad, and taking photos and notes on my camera, all on the seat beside me, and all using the injured shoulder – escalated my shoulder pain to the point where my stress got out of control and made me drive recklessly when I reached the congested zone an hour from the city.
But again on the plus side, pre-monsoon clouds were spreading until they became continuous and were producing rain in the south. And shortly after I arrived at the hotel it was thundering and pouring down, and because I always have rain gear in my pack I was the only guest prepared to cross the courtyard without getting drenched.
I’d recorded a waypoint up there on the ridgetop with my GPS message unit, in a broad clearing where it immediately found a satellite. But amazingly, when I checked it the next morning, it was off by a third of a mile. What could cause such a huge error? That’s really troubling – what if I was snakebit and needed rescue? Apparently this can happen if the device and your mapping software are calibrated differently – but waypoints have been mostly accurate for years, and I’m not aware of any recent changes.
