My 88 year old dad lives alone is in good health, misses my mom who passed a few years ago, lonely, won't go anywhere is just waiting to die.

Colorado...if you want to leave someone a private message, click on their user name. Then you can leave them a message being sure to click the box that checks Private. Although in a forum format, all the answers and comments help all of us.
I live in Colorado and used to live in Florida. I hated Florida and moved back here to Colorado. My folks followed me all around the country until I moved back East and they couldn't afford to, so they moved to Fl. When Dad couldn't drive anymore and had to give up his license, I had to move them back to Colorado in 2011 where I wound up again after living back East. Are you following all the madness? Sigh. Anyway, I had to place both of them in Assisted Living in 2014, Dad passed in 2015 and now mom lives in memory care. Even though she is in memory care, its practically a full time job for me to be handling everything for her including complicated finances.

My point in all this is this......if you feel like dad doesn't need your help or your company now, move back to Colo. Get while the gettings good. He will likely need your help down the line somewhere and you can worry about it THEN. It's a huge job to take on the care and management of a parent, never mind one who's grumpy and uninterested. You are not selfish to want a life of your own so get busy creating one, in the place that makes you happy!
Good luck

Um. There's this: "He is in very good health except for prostate cancer, blocked carotids, and some arthritis." Those exceptions are not what you'd call minor, are they. Are there any investigations or treatment going on?

And then there's this: "Would it be selfish to move back knowing he will be alone without anyone local and have to deal with things by himself?" Actually, that's the wrong question. The *real* question is: is there anything you can do to support your father by living near him that you couldn't do if you were back in Colorado?

If your being nearby is doing nothing to benefit him, there really is naff-all point in your making the sacrifice. But is that strictly true? You don't get any feedback form him, he doesn't seem to appreciate your company, but is it true that he isn't benefiting from your being there?

Of course I can't know, but I think your other sister's basing her refusal to have any contact with him on his "nastiness" while your mother was in memory care is... possibly a bit harsh. Aren't there allowances to be made for the stress and grief and fear he must have been going through at the time? I respect your sister's right to set her boundaries where she thinks best, but I hope she isn't directly blaming him for more than he could help.

Before you move back, which may be the right decision, you need a thorough health review including assessment for dementia (blocked carotids could mean compromised blood supply to the brain could mean vascular dementia, which would explain worsening depression for example - but this is only my amateur guess and you need professional input).

And in any case - what about powers of attorney, health care proxies, advance directives and the rest of the paperwork? Has he seen to that?

Often well-meaning children make promises to their elderly parents surrounding care but they have no idea what they are signing up for and the parent has no clue of the sacrifice they are asking. Another commenter wisely stated that you are not responsible for your dad's happiness. Absolutely true. The rigors of caregiving can't be entered into lightly. If one like your dad hasn't prepared their mind and heart for the inevitability and reality of aging, they will most likely become depressed, even terrified, etc. especially since your dad witnessed your mom's journey through Alzheimer's. If your dad has any mental decline or dementia it can magnify undesirable personality traits. Even an untreated urinary tract infection can cause confusion or magnify any dementia. Also, it would help to know how old you are. Wishing you peace in your heart in whatever you decide.

coloradoproud, it's tough getting old. Sometimes we need to walk in Dad's shoes to see how it feel from his side of the world.

The love of his life is gone so he will be depressed. This isn't how he had planned his old age retirement. I bet all of his friends have either moved away or have passed on. Driving isn't the same.

As we age food doesn't taste the same except for sweets. Our eyesight starts to fade and so does our hearing. Just walking up a flight of stairs can become exhausting. The TV shows aren't the same on the tube. What happened to Ed Sullivan, Lawrence Welk, Leave it to Beaver, type of shows? Today's shows are not that good [I am beginning to sound like my parents].

Telephone's aren't the came. I plan to keep my land-line. When the phone rings, I know how to answer it blindfolded. Even computers can become complex. My Dad use to write code, and then in his 90's, it was difficult for him to remember his password to get into the computer, much less where he had written it down.

My Dad moved to Independent Living at a senior facility as he was tired of trying to maintain a house at 94. He had a beautiful 2 bedroom apartment, large living room, and full-size kitchen. He said he wished he would have moved in years earlier.

My Dad was also a quiet person, happy being surrounded by his books, and watch TV. Only time he would talk with other residents was during dinner in the main dining room. This type of arrangement was cost him $5k per month, which he used the equity from his house to pay the rent. Eventually he needed to move to Memory Care which was in the same complex.

Even though my Dad prefer to be in his room, he liked knowing there were Staff that was checking up on him so he never felt like he was alone. Dad had become a fall-risk.

Does he still drive? How does he gets his groceries, prescriptions, etc? Has he always been a recluse or unsociable? If he went out to socialize before your Mom passed, could it have been just to make her happy?

If he’s always been this way & he was only going out because of your Mom, there’s no changing him now. It sounds like he does keep his mind active so if he’s content to stay home, I think it’s okay. Unless he’s absolutely refusing to take care of necessities! I’m not even a senior & I don’t like going out unless it’s for groceries or yarn.

As for you moving back to Colorado, I have no advice on that.

You have received some good responses here, I don't have much to add, except that my dad was always a loner, it did get worse after his wife died. Unlike your father he was not a grump. He was a pessimist, all his life, I learned to just ignore it and made sure that I would not walk in his footsteps. Don't give up your life for him, you will regret that decision, move on, he will figure it out, cause he only cares about himself, those kind of people always do figure it out.

You can not be responsible for someone else's happiness. I learned this the hard way ( my mom ). Its impossible. My life is so much better since I finally accepted this if they chose to be misrable and alone nothing you say or do will change that.

As I just said on another thread, I will never understand people who wish to lay down as a doormat for those who do not deserve their sacrifice. As you yourself has said, he has always been this way. Why in the world would he change now? The truth is that the end of life is not very pretty even for those of us who love life, and practice being as good to folks as we are able, those of us on the receiving end of decent health and much love; the end of life is about loss. There is a lot of pain and little motivation to get out there and change what you have always done with your life. It is a real option to simple sit about, be reclusive as he always was, do word-find which he enjoys, and wait for the end of what is not, for him, an especially wonderful life (and apparently never was).
Why is this your job to change for him? Are you still hoping that you will disrupt your own life attempting to make his life better in his own mind (which you will never accomplish) so that he will say to you "What a wonderful daughter you are; I wish I had known that all my life; I wish I had realized what a gem you are!" Because that is never going to happen. Is it because all his life he has made you feel guilty and inadequate and it is still working well? Is it so others will think you are a Saint?
Help your father with what HE WANTS HELP with, not what you think he should do with his life. Tell him "If there is something I can do for you please do let me know, Dad, and if I am able I will help you". Then gauge how much you can do without disrupting your own life. Meanwhile send lots of word-find puzzles, and understand that at the end of life not everyone wants to go out there and conquer the world; some are tired. As a nurse it was the hardest job I had, explaining to families of elders, to families of the very ill, that people get TIRED, and just want to move on to a peaceful end to it all. It's an option.