Since winter has returned in many parts of the country, here are a few passages about winter weather getting to and in the mountains.

From William Ashley:
The morning of the 26th [Dec} was cloudy and excessively cold. At 3 o,clock in the afternoon it began to
snow and continued with violent winds until the night of the 27th. The next morning (28th) four
of my horses were so benumbed with cold that they were unable to stand, although we succeeded
in raising them on their feet. A delay to recruit them would have been attended with great danger,
probably even to the destruction of the whole party. I therefore concluded to set forward without
them. The snow was now so deep that had it not been for the numerous herds of buffaloe moving
down the river, we could not possibly have proceeded. The paths of these animals were beat on
either side of the river and afforded an easy passage to our horses. These animals were essentially
beneficial to us in another respect by removing (in their search for food)
the snow in many places from the earth and leaving the grass exposed to view, which was the only
nourishment our horses could obtain.

After an unremitting
and severe labour of two days, we returned to our old encampment with the loss of some of my
horses, and my men excessively fatigued. We found the snow to be from three to five feet in depth
and so firmly settled as to render our passage through it wholly impracticable.

From John Ball, 1832:
Nights clear and cold, often below freezing and days, hot
sun and up sometimes to 80 degrees. But on the 4th of July as we approached and arrived at the
first waters of the Columbia, we had an hour or two of snow.

From John Bradbury:
On 11th June we came in view of the Black hills, and since then have never been out of the sight
of snow. Our clothing requires to be as warm as yours in the coldest winter. During the last three
weeks we have had frost every night, and have frequently encamped by snow banks; yet such a
complaint as a cold is unknown among our men!

From Robert Campbell:
A terrible snow storm came on which lasted several days. We had to go to the Soda Springs on
Bear river, a long distance out of the way. The result was, all our animals died from starvation.
The snow was four feet deep on a level.

Lost Greenhorn, by Alfred Jacob Miller

Other than the passage that indicates the Black Hills, any idea on the location of the other passages you have listed?

The first quote from Ashley was while ascending the southern fork of the Platte River, after leaving the Pawnee villages, very southwest Nebraska nowadays.

The second Ashley quote is form somewhere on the north branch of the Platte in southern Wyoming.

John Ball's writing was four days previous to the Rendezvous at Pierre's Hole, Wyoming.

Robert Campbell was near Sweetwater Lake, in Colorado.

Good Read

Quick story about horses not getting up. Believe it was in the Dakota’s, a young man was wanting to join a cowboy crew on a big round up. Been hanging around with no luck in getting a job. The crew had a knothead horse that would lay down and regardless of what they did would stay there. The crew were standing around this same horse on the ground, scratching their heads when the young man came up. Boss said son if you can get this horse up you’re hired. Young man immediately turned and went to the barn. Came back a couple minutes later with an unhappy barn cat and dropped it straight on the horse. He got the job

That's hilarious.

Robert Campbell was near Sweetwater Lake, in Colorado
Could this be Soda Springs Idaho? Right on the Bear River.

I'd have to reread more of the journal closer. I read sweetwater lake, probably more than one of those out West.

Yep, you are correct, Lost in Utah.
Here's a few lines before the entry quoted above:

They then went to California. Smith and Turner came back poor and joined us the next Summer,
at Sweet Water Lake, which empties into Bear Lake, where the rendezvous of Smith, Jackson and
Sublette was then established.