Graphs of Mountain/Trail Comparisons

[Hikin_Jim]

Wow. Super helpful graphs. Those graphs really lay it out.

So, South Fork via Dry Lake to Gorgonio is three miles longer? About 1.5 miles additional each way? Interesting.

I would love to get a reading on the route I've described on my Six Loops in San Gorgonio post, in particular on the South Fork Loop with the XC short cut up the SE ridge that I've marked in light blue.

It would also be interesting to see the stats for coming up from Fish Creek and using that SE ridge. I'm pretty sure it's going to roughly equalize the trip via Dry Lake with that of via Dollar Lake, and I think it would eliminate about 3 miles from the Fish Creek trip without adding any gain.

HJ

[drndr]

If my math is right the skyline portion of C2C is about 15%? I see about 11 miles for Skyline, some report closer to 9 miles. I imagine the shorter distance may be with the shortcuts but do the shortcuts really take 2 miles off?

Also looks like Vivian Creek's steepness is closest to Whitney, just shorter distance. Though I think Whitney's "hosts" may be nicer

[63ChevyII]

So, South Fork via Dry Lake to Gorgonio is three miles longer? About 1.5 miles additional each way? Interesting.

I have a spreadsheet adding up the mileage of the trail sections (taken from a map), but from what I see from the junction of Dollar & Dry Lake Trails:
Dollar Lake Trail to San G Summit: 6.3 miles one way
Dry Lake Trail to San G Summit: 8.2 miles one way

or a 3.8 mile difference roundtrip. I will double check my maps to make sure I didn't make an error.

I would love to get a reading on the route I've described on my Six Loops in San Gorgonio post, in particular on the South Fork Loop with the XC short cut up the SE ridge that I've marked in light blue.

I don't have a GPX file for that route (up the ridge) but based on what I could do by drawing that shortcut in Google Earth, tracing the trail profile for that section, then adding to the other trail profile, this is what I get:


(click above for fullsize image)

Not having an actual GPX file probably decreases the accuracy some, but the general idea should be as good as the other profiles.

It's funny... every time I pass by that ridge (assuming I am thinking of the same one) I think about going up it. I may have to now, to make sure my graph is accurate

[63ChevyII]

If my math is right the skyline portion of C2C is about 15%?
I see about 11 miles for Skyline, some report closer to 9 miles. I imagine the shorter distance may be with the shortcuts but do the shortcuts really take 2 miles off?

The slope depends on what you believe the mileage to be.

At 11 miles, about 14%
At 9 miles, closer to 19%


I hiked Skyline Friday. The trip computer on my GPS tracked the hike at about 11.2 miles. The save/exported file I got from the GPS puts the hike at 10.7 miles. I try to avoid the obvious shortcuts and I also start from Ramon Road, which adds a 1/2 mile or so.

Since the graphs are principally for my own use, I use the mileages and figures I get from my GPS when possible. For the Skyline Map, I actually wrote down what the Trip Computer reads as I am hiking, that way when I am hiking, I can compare what the map says vs. my GPS to have a good idea of where I am on the trail. On the map I've been working on, I've checked the facts/figures on 3 separate trips.

The variation in mileage really bugs me. Here's an example of how much the mileage can vary from the same GPX file:

From 11/29/13
Garmin Trip Computer: 11.2
Garmin Saved Track (while on GPS): 10.7
Imported in Runkeeper: 10.63
Exported/Converted to Google Earth: 9.38

Is 10.7 the more accurate mileage? Maybe. Is 10.7 more helpful for my personal use? Definitely not. Thankfully all of this is just for fun.

[Hikin_Jim]

Sounds like it might be truncation error?

What model GPS are you using again?

HJ

[63ChevyII]

Sounds like it might be truncation error with trailing digits?

What model GPS are you using again?

HJ

Garmin Dakota 20.

Just for fun I downloaded the C2C gpx file from Shyamal.com:

Shyamal GPX, from Museum:
Skyline: 8.47 miles

My tracks from Dec 2012, using default settings, from Ramon Road:
Skyline: 8.84 miles

My tracks from Dec 2013, trackpoint every 5 secs, from Ramon Road:
Skyline: 11.2 miles

Looking at Shyamal's GPX file in notepad, I think it is same to assume it was created with a Garmin GPS. If the GPX was set to update at the default frequency, I would say that our readings are similar assuming Ramon Road adds about a 1/2 mile to the trip. If this is true, I wonder if it can be assumed that my 'high' mileage on my most recent trips is due to increasing the frequency a trackpoint is created? On my last hike, I set it to every 5 secs I believe. The default frequency is much lower.

[63ChevyII]

Also worth noting (possibly) is that Shyamal states that C2C is 20 miles. When I import it into Google Earth, it is shortened to 18.8.

[Hikin_Jim]

Sounds like truncation. The more accurate result would seem to be from the unsaved track taken with more frequent samples. Once you save it, you're losing some detail and therefore some mileage. At least that's what it looks like.

HJ

[63ChevyII]

I agree. The truncation thing has really annoyed me since I first read about it.

I'm not sure if you saw it (I am thinking you missed it due to all of the replies/questions) but I responded to your questions about 'South Fork Loop.' If it's hard to see, I can change the color of the ridge shortcut.

[Hikin_Jim]

So, South Fork via Dry Lake to Gorgonio is three miles longer? About 1.5 miles additional each way? Interesting.

I have a spreadsheet adding up the mileage of the trail sections (taken from a map), but from what I see from the junction of Dollar & Dry Lake Trails:
Dollar Lake Trail to San G Summit: 6.3 miles one way
Dry Lake Trail to San G Summit: 8.2 miles one way

or a 3.8 mile difference roundtrip. I will double check my maps to make sure I didn't make an error.

OK, so about 1.9 miles one way difference. That's quite a bit.

I would love to get a reading on the route I've described on my Six Loops in San Gorgonio post, in particular on the South Fork Loop with the XC short cut up the SE ridge that I've marked in light blue.

I don't have a GPX file for that route (up the ridge) but based on what I could do by drawing that shortcut in Google Earth, tracing the trail profile for that section, then adding to the other trail profile, this is what I get:


(click above for fullsize image)[/quote] OK, so it looks like my XC route cuts off about a mile each way. I was hoping for a bit more, but alas. Still, cutting two miles off (round trip) is nothing to be sneezed at. And it's what I'd call a "basic" XC route (short, easy navigation, easy negotiation). In other words someone with just decent basic map skills could do it.

It's funny... every time I pass by that ridge (assuming I am thinking of the same one) I think about going up it. I may have to now, to make sure my graph is accurate

It's worth while.

HJ