Those were my criteria and I ended up purchasing a Sony HX-90V on e-bay for under $250. It is small (very pocketable), has an optical zoom of 720mm, and a pop up electronic view finder that works well. Does it take the greatest photographs in the world? No, but they are very good for a camera of diminished size and price. Check it out. The LUMIX DC-ZS70 was my second choice.

Almost without question the best "pocket" camera is the Sony RX100. A word of caution, though, it is not super slim nor will it fit easily into just any pocket. Unless you are big into video the Mark III is the "sweet spot" of price and performance.
I love a true "pocket" camera that will slide easily into any pocket, particularly my front pants pocket. To that end I have to recommend the Canon S120. It has a larger sensor (1/1.7") than most compacts resulting in more low light capability. It shoots in RAW unlike it's successor the S130, JPEG, or both. A great 24-150 lens with a relatively fast f1.8 - f5.7. Plenty of manual features or throw it into Auto and it's a perfect point and shoot. Only drawback is no EVF. Judging by the hard use mine has received it seems very durable.
My 2 cents.......

Great photos of an area where I have spent a lot of time. For anyone who visits the Moab area I strongly recommend Highway 128 from I-70 to Moab. Has to be one of the top ten drives in the U.S.

We now live in a world where literally everyone is a photographer (picture taker). Tens of millions of photos are being uploaded daily to sites like Flicker, Picasso, Facebook, Instagram, camera model specific blogs and chat groups, to name only a few of hundreds. I have come to recognize that even some of the greatest photos I see and certainly all of my own best shots end up buried in these cyberspace repositories. The upshot is that almost everyone is inundated and photo saturated to the point of almost being numb to the any creative artistry that might be out there. People using Facebook tell me that they don't have time to view and appreciate the social photo sharing from friends and relatives, let alone the energy to delve into photos that might be inspirational, thought provoking, or just beautiful art. When sharing my own photos, even pared down to the very few most interesting, it seems my friends and even my wife are just being accommodating when looking at my pictures. When was the last time you went to a party, out to dinner, or were just hanging out with people that someone did not take out their cell phone to show a picture they took or downloaded? How much interest in that did you really have?
As I am entering retirement I thought it would be challenging to bolster my photographic skills and spend more time in the pursuit of meaningful photography. I realize that, for the most part, no one except me is going to appreciate the images. Even here on UHH I suspect few of us take the time to download and admire even the best shots that are posted. All that to say that I will carry my camera, try to be available during the best times of the day, record the beauty and uniqueness of the world that I see, and simply enjoy the learning and challenges that come with trying to take good pictures. Enjoy!

Just returned. Don't pay ANY attention to weather reports.....period. All of the naturalists say that and my experience reinforced that sentiment. Might want to check out a GAdventure tours. They lease four boats, their tours are active, and affordable.

Just returned a couple weeks ago. You will almost always be with a "group", so travel with minimal gear. As the there won't be leisurely time to switch lenses, use a tripod, or make multiple exposures I would have the 24-105 as your primary set up. Can't emphasize the importance of taking the time to drop the camera and any other water sensitive devices in a simple dry bag. We did a lot of "wet landings" and witnessed a couple people getting swept to shore in the surf. Have a great trip....you will love the Islands.

Just returned from 10 days on a live-aboard in the western Galápagos. Most comments above are right on. I used an FZ1000 and nothing else. You may want a waterproof point and shoot for snorkeling. Minimize your gear.
Just want to emphasize that you are likely to be doing "wet-landings" which can result in a tumble in the surf. I took 30 seconds before every trip in the dinghy to throw my camera and binoculars in a small dry bag....just in case. One of our group did get "washed ashore". Fortunately she had a dry bag in her backpack so camera and cell phone survived.
Great trip. It's a marvelous opportunity to understand biological processes and and to gain insights into how all of life is interconnected. I continue to be amazed at Charles Darwin's insights from so long ago that modern science verifies and is now the basis of all biology, much of medicine, and even used in psychology and sociology. Enough said.

I would just be guessing, but I think with longer exposures you should be able to capture the cliff sides and river as well as the stars/Milky Way.

I would seriously consider going to Dead Horse Point State Park. There will be many options to frame the Milky Way. There is good potential for a shot of the Milky Way above and a glimmer of the river in the canyons below.
Good Luck!