Eureka Lodge is located at ~10,000', and the nearest town of Silverton is at 9,300'. If you have never travelled to elevation before, you should do a little research to prepare.
Altitude sickness can set in at as low as 8,000'. The nearest hospital is 1.5 hr drive. Know the signs!
Headache
Fatigue
Dizziness
Nausea
Loss of coordination
Can't think straight
The best prevention is slowing your ascent - even better of a reason to spend a night in Durango first. Besides that, the effects of altitude can be exacerbated by
Lack of sleep
Hydration
It is very important to stay more hydrated than normal - this means you should be drinking an extra 1-1.5 liters of water per day beyond the normal amount!
Alcohol
Likewise, alcohol also affects you more. Some say 2 beers feel like 4
Lack of food
The climate is very dry, even though it can rain every day. This is why you need to remember to hydrate. Bring chapstick, lotion, vaseline, etc.
The historical average high temperature is 72°F in July and at night it could drop into the 30s. Yes, this is a summer wedding, but remember you will be in a mountain valley and the temperature will start to plummet as soon as the sun drops behind the mountain.
With how strong the sun is at this altitude, 72° can feel pretty hot (it often feels 10-15°F warmer than it actually is in the sun). The lodge does not have air conditioning, but it often stays quite cool inside in the shade.
The one exception is Ouray for our Saturday trip. It's much lower elevation and get HOT, average high of 78°F
July and August are the rainiest months. The Colorado Rockies are additionally notorious for severe thunderstorms everyday around 1-2 pm until early evening; you MUST return below treeline by this time if on a hike.
Snowfall also is not out of the question.
Do not use just any weather app for forecasts - they are notoriously wrong in the mountains. You should use OpenSnow for Eureka, CO. Further, don't rely on the forecast too much. It could say sunny with 0% chance of rain and then could be a severe thunderstorm lasting all day.
The sun is SCORCHING at these altitudes. You will burn very quickly and it will feel 10-15°F higher in the sun than the air temp reading. We will have sunscreen onsite, but we encourage you to bring your own if you favor a particular type/brand. A small travel umbrella or sun hoodie can help cool you down and protect you from the sun.