Miller made two trapping related illustrations – Setting Traps for Beaver and Trapping Beaver. The former, his preparatory sketch, left an empty space where he would eventually paint the trap. Art historian Lisa Strong surmised Miller may have forgotten what a single-spring trap looked like when it was set. Indeed, traps seldom appear in Miller’s works.
It is doubtful Miller observed mountaineers trapping beaver. The supply caravan the artist accompanied could not spare time from its travel schedule to bother with beaver. And there is little evidence men trapped during rendezvous. Miller left the Green River long before trappers headed back into the field to resume hunting.
Further, the artist noted:
Foot prints of the [beaver] on the mud or sand are carefully searched for, and if fresh, they then prepare to set their traps. One of these is baited with “medicine” - hidden under water, and attached to a pole driven firmly on or near the bank. A “float-stick” is made fast to the trap, so that if the Beaver should carry it away, the stick remains on the surface of the water and points out its position.
Compare trapper Joseph Meek’s description of the process:
He has an ordinary steel trap weighing five pounds, attached to a chain five feet long, with a swivel and ring at the end, which plays round what is called the float, a dry stick of wood, about six feet long. The trapper wades out into the stream, which is shallow, and cuts with his knife a bed for the trap, five or six inches under water. He then takes the float out the whole length of the chain in the direction of the centre of the stream, and drives it into the mud, so fast that the beaver cannot draw it out; at the same time tying the other end by a thong to the bank. A small stick or twig, dipped in musk or castor, serves for bait, and is placed so as to hang directly above the trap, which is now set … In placing the bait, care must be taken to fix it just where the beaver in reaching it will spring the trap.
Though similar, the biggest contrasts between the descriptions is how the trap is baited and where the anchor pole is driven. Miller described putting the attractant on the trap, placing it under water, then pounding the pole into the bank – a process which would fail every time. Meek, more accurately, pushed a bait-tipped stick into the muddy shoreline at a determined distance from the trap to snare the animal’s foot as it stops and stretches to smell it. Meek stretched the chain’s full length into deeper water, away from the shore, before securing it in the stream bottom.
Miller did not fully comprehend how the trapping method worked. Mountaineers may have found a spot along Horse Creek to pose or demonstrate the procedure, but trappers staging their familiar technique apparently did not translate well to the artist’s understanding. Miller captured the essence and look of the scene, reinforcing the value of his images regardless of errors in his written description. Nevertheless, this remains the closest visual depiction to the primary period skill that drove the Rocky Mountain fur trade.