Drink a lot of water! Drink alcohol slowly, it catches up with you faster.
Yes! Wear walking shoes and layers. It can go from cool in the morning in Colorado to hot in the afternoon, back to cool in the evenings.
June brings warm summer temperatures in Colorado that draw tourists from all over the country to its wilderness and natural beauty. Average high temperatures are between 70°F (21.1°C) to 87°F (30.6°C), while the average low temperatures are within 35°F (1.7°C) to 55°F (12.8°C) range.