Kyle, for a long time I was sponsered as a cyclist and I found most manufacturers are constantly bombarded with request to test equipment. The hoops one has to jump through are enormous to get much of anything in your hands.
The outdoor industry is in the same state, for a long time I would request guide discount and even that was a pain.
Approach backcountry gear test, even backpacker magazine [ the name that sticks in my mine is Kristen Hostetter] but I would start also at local level networking with your nearby outdoor store, these are the people who purchase the stuff so the makers respond a little better then a blind contact, the regional sales people can sometimes swing a deal.
You have to bring something to the table; a resume of hikes, a plan of new hikes with conditions expected, why you think this would be the perfect venue to test their stuff, and some writing ability. Good luck.