Take advantage of where you are! I have easy access to a long path along the Charles River in Cambridge – I’d love to spend more time in Colorado mountain trails, but I also enjoy running on flat.
Races are valuable commitment devices & motivators. It may be a while until large events come back, though. You might consider finding another training milestone or goal. For example – could you accumulate 150 hours of Zone 1 aerobic work through the rest of 2020? (Or 200 hours, or 300 hours, depending on your level of training.) If that means hiking – great!
Set yourself up for emotional success as well as training success. Hiking in Z1 on Colorado trails at 8,000-12,000 feet will definitely build up aerobic capacity that will translate to improved running capability. It won’t be specific training, but definitely good base / general training.