Mammoth Trail Closure

[HooKooDooKu]

I was unable to get a JMT permit to go over Donahue Pass, but I could get a permit that would allow me to start at Happy Isle, cross Isberg Pass, and rejoin the JMT at Devils Post Pile. The final leg of this path includes using Mammoth Trail to reach Devil's Post Pile. But the Sierra National Forest currently lists the trail as closed with no reason given. The current closure order is listed on the following webpage, and indicates the closure is from March 2, 2024 thru May 2, 2024. But with no reason given, I have to wonder about the possibility that the closure might be extended into the summer.
https://www.fs.usda.gov/alerts/sierra/a ... ?aid=86233

[Wandering Daisy]

I am not sure where "Mammoth Trail" is. But once over Isberg Pass- you have to cross the San Joaquin. Hemlock Crossing bridge is out. Additionally clean up from a forest fire may be happening, since it specifies a lot of the roads in the area that were also impacted by the fire. There is also construction weekdays in Devils Postpile.

Regardless, the route does not look very appealing to me. I am surprised they would even give you a permit for that route. If I could not get a permit to go over Donehue Pass, I would continue up to Tioga Pass and go south over Parker Pass-Alger Lakes and then up Rush Creek to the PCT just south of Donehue Pass. This is a much more scenic route and gets you back on the PCT sooner.

[Snowtrout]

The Mammoth trail has been closed for at least a year, if not longer, plus a lot of campgrounds due to the Creek Fire. Since the road heading into Mammoth Pool reservoir has been closed past the Redinger Lake outlook, I doubt anyone has been in there lately to do anything to get thecampgrounds and trails open for this year.

[HooKooDooKu]

I got to speak to someone at the Bass Lake Ranger District today.
Based on our conversation, it sounds like they "plan" to "try" to open the trail this year (my words, not a direct quote).

[HooKooDooKu]

I am surprised they would even give you a permit for that route.

I wasn't given a permit "for that route". I simply got the Yosemite "Haapy Isle to Illiluette Valley" permit with a Whitney Portal exit. Of course the only legal way to get to Whitney on such a permit would include using Mammoth Trail to get to Devils Post Pile.

[Wandering Daisy]

I would make a bit of a fuss to Yosemite Wilderness office. They need to work with you and come up with a permit for an alternate route if the trail is closed. I would not even start out without a 100% sure guarantee. Getting stopped dead where the Mammoth trail starts will leave you in a horrible situation. Even if the trail is open be sure you can safely cross the river. The Parker Pass route is a good alternative- see if they can work with you for that or put you on a priority for any Donehue JMT permits from Tuolumne that is cancelled.

There are off-trail routes out of Yosemite with an Illouette permit-- just short of Iseberg Pass, take the trail that goes north to Lyell Fork of the Merced, turn up to Forrester Pass just before you drop to the Lyell Fork, and then take Roper's High Route to Thousand Island Lake. You already have the Whitney Exit. The 1-2 days off trail is complex and requires good micro-route finding but stays class2 if you are on route. Not that I am recommending this because I do not know your skills.

[mtnsteiger]

Mammoth Trail starts at the end of the road 5S30, east of Isberg trailhead, goes over Sheep Crossing bridge and on eventually to Devils Postpile.

With the Hemlock Crossing bridge out, you can’t get across the river there to reach the Mammoth trail. Instead you’d have to hike all the way out to Isberg trailhead, then walk the road east to Mammoth trailhead. Lots of walking through very bad fire damaged areas. This would be if the Mammoth trail is even open, which apparently it’s not.

I agree with WanderingDaisy, try to use Parker Pass.