Colorado LiDAR Findings

[supranihilest]

Mike and Ben, thanks for providing more examples!

Was typing as you answered. I agree!

Didn't know this about showing the ranked summit as the true summit on LoJ when the benchmark is off the summit. Good to know, and makes sense.

I didn't know this either. It makes sense for ranked peaks. If the benchmark location isn't ranked but a nearby higher point is, then the benchmark location simply isn't ranked. It's a matter of pure numbers. It obviously gets weird when things are unranked. It sounds like for unranked peaks literally any arbitrary point could be the "peak." Elevation doesn't matter. I personally disagree, but I do see the logic. I see Sheep as different from Lone Eagle, to use those examples, but I don't actually know if I could articulate why since they're basically the same - unranked, named, lower elevation points along a ridge with higher point above the named point. That said, it gets even weirder when you consider ranking criterion, the 300-foot prominence criterion, is arbitrary as well. In the example of "Hawk Peak" it's almost like the benchmark should be considered a separate peak from the peak. If we lower the prominence for rank to 200 feet then Sheep would presumably then be considered the eastern nub, not the benchmark. Yeah, I'm getting off into the land of hypotheticals, but still, it does seem somewhat arbitrary to me. Why should unranked peaks be treated different from ranked? Why have two separate sets of rules? I'd still consider Sheep as a whole to be everything from the low point on the ridge to "Lake Point" all the way to Lizard Head Pass - that's how we treat something like "Hawk". But now I'm just rambling.

Thanks for the discussion.

Quick & dirty analysis of this area shows that the spire-like HP is still unranked with 227 ft of prominence, but given that old map, maybe it's Sheep Mountain's original summit...

Hey Ryan, since you're in the area - see anything interesting for the San Miguel-V9 ridge?

I'm not seeing anything there, I'm afraid. Only picking up 183 of prominence for PT 13269 (LiDAR comes in at 13,277) based on the saddle just to its west.

Thanks for checking, Ryan. I was hoping to find something there, guess I'll have to go build a 117-foot tall cairn on top.

[bdloftin77]

I'm not seeing anything there, I'm afraid. Only picking up 183 of prominence for PT 13269 (LiDAR comes in at 13,277) based on the saddle just to its west.

Thanks!

[bdloftin77]

Why should unranked peaks be treated different from ranked? Why have two separate sets of rules?

Yeah, that's a good question. When the benchmark is close to the actual summit, it's easy - same name. If the benchmark is further from and lower than the summit, we call the high summit point "unnamed elevation." If the higher summit not containing the benchmark is ranked, we suddenly shift the benchmark name to the higher summit. I'm not sure why we don't call the higher ranked summit "unnamed elevation." Perhaps this is because there would have to be an arbitrary distance threshold from the benchmark to the summit to suddenly change the ranked summit to an unnamed summit? Or if the summit is contained in a different contour, maybe this would be the distinguishing factor?

We'd probably have to infer the intention of the naming behind the benchmark. Are they trying to call the whole mountain by that name? Or are they trying to call a certain feature by that name? If the whole mountain, then it seems fine to shift the name from the benchmark to the ranked high point. But this would have to apply to benchmarks on clearly unranked locations as well. If they were trying to refer to that whole mountain as Sheep Mountain, then yes, the highest point would need to shift to what we found by lidar. But if they are only referring to that sub-summit as Sheep Mountain, then it would be okay to call the actual higher point found by lidar as "unnamed elevation."

Hopefully that made sense.

[Candace66]

Speaking of actual high points, John found that the high point of 13660 (north of Ellingwood Point) is actually south of the previously known location. He got a tip from Gerry Roach that someone had found this new spot to be higher. Turns out it's about 2.5 feet higher than the old one. This new location is on the lidar page.

Roach mentioned this issue in the second edition of his13ers guidebook. Which inspired me to ask about it on the forum in 2018. Now we have LiDAR to sort it out!

viewtopic.php?f=2&t=55400

So, eventually, the "13660" pin will be moved from the high point where it has been, to the point labeled 13618 on the topo? (I just checked and nothing has changed yet.)

[bdloftin77]

Speaking of actual high points, John found that the high point of 13660 (north of Ellingwood Point) is actually south of the previously known location. He got a tip from Gerry Roach that someone had found this new spot to be higher. Turns out it's about 2.5 feet higher than the old one. This new location is on the lidar page.

Roach mentioned this issue in the second edition of his13ers guidebook. Which inspired me to ask about it on the forum in 2018. Now we have LiDAR to sort it out!

viewtopic.php?f=2&t=55400

So, eventually, the "13660" pin will be moved from the high point where it has been, to the point labeled 13618 on the topo? (I just checked and nothing has changed yet.)

If you click on the summit elevation link in the lidar page, it'll direct you to the map with the new summit location centered (same with clicking on the saddle elevations, if they're there). The high point is in the highest closed contour between 13618 and the former presumed HP location. Glad we could finally answer this for you!

Once entire elevation levels are completed on the lidar page (say, every new ranked 14er, every ranked 13er), then John'll finally transfer over the new elevations and locations to the actual peak pages.

Lidar data for northern Colorado probably won't be available for download til late summer or fall of this year, per an email from the USGS.

[Bombay2Boulder]

What's the story on Sheep's ladder? That's a first for me. I really hope V9's summit doesn't change, that's the junkiest of the junk ridges in the San Miguels.

[Candace66]

If you click on the summit elevation link in the lidar page, it'll direct you to the map with the new summit location centered (same with clicking on the saddle elevations, if they're there). The high point is in the highest closed contour between 13618 and the former presumed HP location. Glad we could finally answer this for you!

Ah, okay, I hadn't tried clicking on the LiDAR elevation!

Roach's statement was, "there is some evidence that Point 13618...southeast of Point 13660, is actually higher than Point 13660."

But per LiDAR, the highest point is not 13618, but a point along the ridge. It's marked on this map by the little black crosshairs (I added a blue arrow for emphasis).

13660 by Candace66, on Flickr

[bdloftin77]

If you click on the summit elevation link in the lidar page, it'll direct you to the map with the new summit location centered (same with clicking on the saddle elevations, if they're there). The high point is in the highest closed contour between 13618 and the former presumed HP location. Glad we could finally answer this for you!

Ah, okay, I hadn't tried clicking on the LiDAR elevation!

Roach's statement was, "there is some evidence that Point 13618...southeast of Point 13660, is actually higher than Point 13660."

But per LiDAR, the highest point is not 13618, but a point along the ridge. It's marked on this map by the little black crosshairs (I added a blue arrow for emphasis).

13660 by Candace66, on Flickr

Yep! In the thread you linked to, John mentioned the same thing about the closed contour possibly being the highpoint, not 13618.

And no worries! I didn't know that for a little while either about the lidar elevations being links to the new map locations.

[RyanSchilling]

Why should unranked peaks be treated different from ranked? Why have two separate sets of rules?

They really don't have different rules, as the definition of prominence doesn't care what arbitrary cutoff we use to distinguish ranked from unranked. Sheep Mountain's summits would have the same prominence whether we used a 100-foot rule or a 1000-foot rule.

[RyanSchilling]

If you click on the summit elevation link in the lidar page, it'll direct you to the map with the new summit location centered (same with clicking on the saddle elevations, if they're there). The high point is in the highest closed contour between 13618 and the former presumed HP location. Glad we could finally answer this for you!

Ah, okay, I hadn't tried clicking on the LiDAR elevation!

Roach's statement was, "there is some evidence that Point 13618...southeast of Point 13660, is actually higher than Point 13660."

But per LiDAR, the highest point is not 13618, but a point along the ridge. It's marked on this map by the little black crosshairs (I added a blue arrow for emphasis).

13660 by Candace66, on Flickr

Yep! In the thread you linked to, John mentioned the same thing about the closed contour possibly being the highpoint, not 13618.

And no worries! I didn't know that for a little while either about the lidar elevations being links to the new map locations.

*grumble* Another "undone" peak for me, haha. Though I can't complain too much about revisiting Lily Lake someday.

[supranihilest]

Why should unranked peaks be treated different from ranked? Why have two separate sets of rules?

They really don't have different rules, as the definition of prominence doesn't care what arbitrary cutoff we use to distinguish ranked from unranked. Sheep Mountain's summits would have the same prominence whether we used a 100-foot rule or a 1000-foot rule.

I know that, that's pure fact of physical reality. Any point has the prominence that it has. It's tautological. My point was that Sheep's "summit," where the benchmark is, is lower than a point along the ridge that makes up Sheep-at-large. Using ChicagoTransplant's example of "Hawk Peak", however, the summit is higher than the benchmark. The only differences are the former is unranked and the latter ranked; the former's ridge high point is farther from the benchmark, the latter's high point closer. So they have different rules as far as what we consider to be the point worth tagging. In Sheep's case it's the lower benchmark. In "Hawk"'s case it's the higher unmarked point. Actual prominence should be irrelevant in my opinion, it's what point has a higher elevation that matters. At least in my mind!

[Chicago Transplant]

Yeah, me too on 13660. I didn't go out and back to that random mid-point that is checking in higher. Looks like a return trip, maybe when I go for LiDAR added 13555 I'll make a weekend of it to head over there too.

I did go out and back to V9's west summit, I noted in my TR that it was 2+ and that it was lower than the eastern one. But that is just based on my feeling from standing on both, I didn't level anything.