Useful map and information

[Wandering Daisy]

https://www.fire.ca.gov/incidents/2020

This map shows the extent of wildfires for 2016 to present. Scroll to the bottom to change the date. Although I was initially looking for recent burn data for areas I plan to backpack this summer, I realized that the base map is also very useful. It appears to have recent trail locations, bridges, fords, streams, tributary streams that you can zoom in for details. It does not have topography. Perhaps you can turn on a topo layer, but I have not played with it much. It is a very good supplement to topo maps.

If you are familiar with this map, what is the base map? I have never heard of "open street map".

[c9h13no3]

Open Street Map (or OSM for short) is just what it sounds like: an open source map. Anyone can edit it, similar to Wikipedia.

Caltopo, Alltrails, Gaia, ect. often pull data in from OSM, and display it in various ways. So you've probably looked at it in some form before. But because few folks use the actual Open Street Map to plan trips, you also see whatever else Gaia/Alltrails/Caltopo puts on top of it (or removes).

I linked to it in this thread, but it must not have caught your eye .

[Wandering Daisy]

I did post on that 2023 entry- and likely my eyes glazed over reading some of the subsequent posts. I do get overwhelmed with all this new technology.

In your opinion, how much can I trust the details on this map? I checked out Bear Diversion trail up to Bear Basin and was glad to see fords marked and detail on the trailheads including Bear Creek Cross Trail. It was interesting that they show an upstream "detour" route where the PCT crosses Bear Creek. I doubt it is a "trail" but it would be nice if I knew it was obtained from good GPS data or just estimated. I have actually short-cut to Lou Beverly Lake but a ways upstream. The USGS maps are dated, so that tells when the trail location was determined. I know that a lot of the USGS trails are no longer maintained and much on USGS maps is no longer accurate.

I was amazed at the size and impact of some of the recent fires. Yosemite area seems to really get hit hard with the fires. So sad.

[c9h13no3]

In your opinion, how much can I trust the details on this map?

In the early days of Wikipedia, with a small community of editors, the information wasn't as quality. Open Street Map is kinda in that phase.

For example, the climber's descent from DAFF dome was shown on the map as a trail a while back. However, it usually involves a rappel off the East face. So I edited that out. It has been improved since, to the current state below. So the information is generally pretty good, especially in places people visit more often. But it is still a work in progress. But I'd say that given how fast the wilderness changes, this approach has a better shot at providing an up to date map than the USGS does

DAFF_Area.png

[shawnterustic]

In your opinion, how much can I trust the details on this map? I checked out Bear Diversion trail up to Bear Basin and was glad to see fords marked and detail on the trailheads including Bear Creek Cross Trail. It was interesting that they show an upstream "detour" route where the PCT crosses Bear Creek. I doubt it is a "trail" but it would be nice if I knew it was obtained from good GPS data or just estimated. I have actually short-cut to Lou Beverly Lake but a ways upstream. The USGS maps are dated, so that tells when the trail location was determined. I know that a lot of the USGS trails are no longer maintained and much on USGS maps is no longer accurate.

I tend to take everything with a grain of salt, but they do seem to be decently accurate when compared to real-life experiences in most places. That particular "detour" is likely based on Andrew Skurka's published high water detour suggestions for the JMT/PCT corridor - people used it early season last year before Bear Creek levels went down (although I was still surprised to arrive at the PCT crossing of Bear Creek in early-ish August and find the water just above my knees - what year!)

[Enigmagic]

In your opinion, how much can I trust the details on this map? I checked out Bear Diversion trail up to Bear Basin and was glad to see fords marked and detail on the trailheads including Bear Creek Cross Trail. It was interesting that they show an upstream "detour" route where the PCT crosses Bear Creek. I doubt it is a "trail" but it would be nice if I knew it was obtained from good GPS data or just estimated.

Most of the trails in the high Sierra, excluding climbing routes, are way more accurate than the USGS maps. I added the Bear Creek detour after a 2019 trip based on a Skurka map and adjusted it slightly after following along again in early July 2023. There is a use trail for a short while following the Lou Beverly outlet and some sizable logs over the East Fork Bear Creek. Pretty easy cross country but definitely not a trail. The Sierra NF ranger we bumped into was recommending this instead of crossing at the trail. There are downstream alternatives much less dangerous as well.

If you find any major errors in the map anywhere around there let me know and I will try to fix them.