Jonathan I knew I would find the reference to the "pantaloons" if I just kept up the search in my library.
Bingo - found that reference about a young man named Osborne Russell (1834).
Outfit of a Trapper
<h2 class="post-content">Osborne Russell's Purchases at Fort Hall</h2>
<h3 class="post-content">
Introduction</h3>
In the spring of 1834, a young man named Osborne Russell hired on with the Columbia River Fishing and Trading Company to hunt in the Rocky Mountains. He kept a detailed diary of his experiences in the mountains, and later these notes were published as Journal of a Trapper.
Some of the men bought part of their personal outfit from the company before they left. Russell bought $54.37½ worth of goods from the company, but a "small ledger" detailing these items is not available. But several of his peers bought goods that were itemized in the surviving ledger 1, and represent the type of goods available to, and popular with the men as they prepared for the journey.
<table class="MsoNormalTable" style="width:73.0%;mso-cellspacing:1.5pt;mso-yfti-tbllook:1184" border="0" cellpadding="0" cellspacing="3" width="73%"><tr style=><td style="width:19.0%;padding:.75pt .75pt .75pt .75pt" width="19%">
Date</td><td style="width:25.0%;padding:.75pt .75pt .75pt .75pt" width="25%">
Name</td><td style="width:30.0%;padding:.75pt .75pt .75pt .75pt" width="30%">
Description</td><td style="width:10.0%;padding:.75pt .75pt .75pt .75pt" width="10%">
Amount</td><td style="width:14.0%;padding:.75pt .75pt .75pt .75pt" width="14%">
Pg. in Jrnl.</td></tr><tr style=><td style="padding:.75pt .75pt .75pt .75pt">
4-Apr</td><td style="padding:.75pt .75pt .75pt .75pt">
Samuel Nott</td><td style="padding:.75pt .75pt .75pt .75pt">
1 blkt</td><td style="padding:.75pt .75pt .75pt .75pt">
$3.50
</td><td style="padding:.75pt .75pt .75pt .75pt">
7
</td></tr><tr style=><td style="padding:.75pt .75pt .75pt .75pt">
15-Apr</td><td style="padding:.75pt .75pt .75pt .75pt">
Samuel Nott</td><td style="padding:.75pt .75pt .75pt .75pt">
1 capot</td><td style="padding:.75pt .75pt .75pt .75pt">
$11.00
</td><td style="padding:.75pt .75pt .75pt .75pt">
7
</td></tr><tr style=><td style="padding:.75pt .75pt .75pt .75pt">
15-Apr</td><td style="padding:.75pt .75pt .75pt .75pt">
Samuel Nott</td><td style="padding:.75pt .75pt .75pt .75pt">
1 pr pantaloons</td><td style="padding:.75pt .75pt .75pt .75pt">
$5.00
</td><td style="padding:.75pt .75pt .75pt .75pt">
7
</td></tr><tr style=><td style="padding:.75pt .75pt .75pt .75pt">
15-Apr</td><td style="padding:.75pt .75pt .75pt .75pt">
Samuel Nott</td><td style="padding:.75pt .75pt .75pt .75pt">
2 pr drawers (pantaloons)</td><td style="padding:.75pt .75pt .75pt .75pt">
$3.00
</td><td style="padding:.75pt .75pt .75pt .75pt">
7
</td></tr><tr style=><td style="padding:.75pt .75pt .75pt .75pt">
15-Apr</td><td style="padding:.75pt .75pt .75pt .75pt">
Samuel Nott</td><td style="padding:.75pt .75pt .75pt .75pt">
1 pr socks</td><td style="padding:.75pt .75pt .75pt .75pt">
$0.50
</td><td style="padding:.75pt .75pt .75pt .75pt">
7
</td></tr><tr style=><td style="padding:.75pt .75pt .75pt .75pt">
15-Apr</td><td style="padding:.75pt .75pt .75pt .75pt">
Samuel Nott</td><td style="padding:.75pt .75pt .75pt .75pt">
1 wool hat</td><td style="padding:.75pt .75pt .75pt .75pt">
$1.25
</td><td style="padding:.75pt .75pt .75pt .75pt">
7
</td></tr><tr style=><td style="padding:.75pt .75pt .75pt .75pt">
15-Apr</td><td style="padding:.75pt .75pt .75pt .75pt">
Samuel Nott</td><td style="padding:.75pt .75pt .75pt .75pt">
1 blkt</td><td style="padding:.75pt .75pt .75pt .75pt">
$3.50
</td><td style="padding:.75pt .75pt .75pt .75pt">
7
</td></tr><tr style=><td style="padding:.75pt .75pt .75pt .75pt">
15-Apr</td><td style="padding:.75pt .75pt .75pt .75pt">
John Ward</td><td style="padding:.75pt .75pt .75pt .75pt">
1 blanket coat</td><td style="padding:.75pt .75pt .75pt .75pt">
$11.00
</td><td style="padding:.75pt .75pt .75pt .75pt">
11
</td></tr><tr style=><td style="padding:.75pt .75pt .75pt .75pt">
15-Apr</td><td style="padding:.75pt .75pt .75pt .75pt">
John Ward</td><td style="padding:.75pt .75pt .75pt .75pt">
2 flannel shirts</td><td style="padding:.75pt .75pt .75pt .75pt">
$4.00
</td><td style="padding:.75pt .75pt .75pt .75pt">
11
</td></tr><tr style=><td style="padding:.75pt .75pt .75pt .75pt">
15-Apr</td><td style="padding:.75pt .75pt .75pt .75pt">
John Ward</td><td style="padding:.75pt .75pt .75pt .75pt">
1 pr drawers</td><td style="padding:.75pt .75pt .75pt .75pt">
$1.50
</td><td style="padding:.75pt .75pt .75pt .75pt">
11
</td></tr><tr style=><td style="padding:.75pt .75pt .75pt .75pt">
15-Apr</td><td style="padding:.75pt .75pt .75pt .75pt">
John Ward</td><td style="padding:.75pt .75pt .75pt .75pt">
1 pr pantaloons</td><td style="padding:.75pt .75pt .75pt .75pt">
$5.00
</td><td style="padding:.75pt .75pt .75pt .75pt">
11
</td></tr><tr style=><td style="padding:.75pt .75pt .75pt .75pt">
15-Apr</td><td style="padding:.75pt .75pt .75pt .75pt">
John Ward</td><td style="padding:.75pt .75pt .75pt .75pt">
1 pr blanket</td><td style="padding:.75pt .75pt .75pt .75pt">
$7.00
</td><td style="padding:.75pt .75pt .75pt .75pt">
11
</td></tr><tr style=><td style="padding:.75pt .75pt .75pt .75pt">
16-Apr</td><td style="padding:.75pt .75pt .75pt .75pt">
John Maxwell</td><td style="padding:.75pt .75pt .75pt .75pt">
1 pr blankets</td><td style="padding:.75pt .75pt .75pt .75pt">
$8.00
</td><td style="padding:.75pt .75pt .75pt .75pt">
5
</td></tr><tr style=><td style="padding:.75pt .75pt .75pt .75pt">
26-Apr</td><td style="padding:.75pt .75pt .75pt .75pt">
John Maxwell</td><td style="padding:.75pt .75pt .75pt .75pt">
1 capot</td><td style="padding:.75pt .75pt .75pt .75pt">
$10.00
</td><td style="padding:.75pt .75pt .75pt .75pt">
5
</td></tr></table>
Townsend made another observation describing how the men camped while preparing for the journey that suggests that the men apparently all used tents, and that each one was equipped with some sort of lantern or candle: "The men of the party, to the number of about fifty, are encamped on the bank of the river, and their tents whiten the plain for the distance of half a mile... The beautiful white tents, with a light gleaming from each, the smouldering fires around them, the incessant hum of the men, and occasionally the lively notes of a bacchanalian song, softened and rendered sweeter by distance."
Thank you Mr. Russell