Combine the trail mix and water and let soak for at least three hours. Once soaked, strain out the trail mix and add water to measure a total of four cups (reserve trail mix).
Put trail-mix-infused water, sugar, and huckleberries in a saucepan and cook until sugar is dissolved. Place into blender or food processor and add reserved trail mix, blend until emulsified. Strain into a container and store in the fridge.
Fill a rocks glass with crushed ice.
Add all of the cocktail ingredients to a shaker and shake until combined. Strain over ice into the glass.