Even the clearest mountain streams may be unhealthy to drink because of mine wastes, bacteria and viruses, or a single-celled organism called Giardia lamblia. This microorganism causes intestinal distress in the way of severe diarrhea, nausea, cramps, and loss of appetite. In short, it will make your life miserable for weeks if not treated medically. It becomes introduced to surface waters from animal and human waste. To be safe, avoid all surface waters and carry plenty of water with you.
Hunters wear neon orange for a reason.
You should do the same if you insist on biking off-road during the autumn hunt. Avoid the opening and closing days of hunting season, stay on main dirt roads, and forfeit remote single-tracks. Utah has a deep mining heritage centered about yesteryear's mining activity in desert and alpine terrain alike. Old mining camps, structures, tunnels, and shafts may spark curiosity, but entering one is backcountry roulette. Structures may exist in a state of decay and collapse.