All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.
Visiting graves is valid under Sharee‘ah and even favorable because it reminds the visitor of the Hereafter. This is why the Prophet, sallallaahu ‘alayhi wa sallam, commanded doing it after having previously forbidden it. It is narrated that the Messenger of Allaah, sallallaahu ‘alayhi wa sallam, said: “I had previously forbidden you to visit the graves. But now visit them (if you so like).” [Muslim and others] and “since it reminds you of the Hereafter,” according to another narration.
Meanwhile, surpassing the mentioned distance is regarded a journey and setting out on a journey only to visit graves belongs to what is forbidden of journeys (for a religious service) except the three masjids.
We advise you, after fearing Allaah The Almighty, to supplicate to a good effect for your father, give in charity on his behalf, maintain his ties of kinship and deal generously with his friends.
It is narrated that the Messenger of Allaah, sallallaahu ‘alayhi wa sallam, said: “If the son of Aadam dies, all his deeds cease except for three: recurrent charity, an advantageous knowledge by which the people benefit or a righteous child to supplicate for him.” [Muslim]
It is narrated that a man asked the Messenger of Allaah, sallallaahu ‘alayhi wa sallam, “O Messenger of Allaah, does there remain anything of my dutifulness towards my parents therewith to do good to them after their death?” He, sallallaahu ‘alayhi wa sallam, said: “Yes. It is to invoke (Allaah’s) blessing upon them, ask for (Allaah’s) forgiveness for them, carry out their covenants after their death, deal generously with their friends (for their sake) and maintain ties of kinship which are not maintained except through them.” [Ahmad]
We ask Allaah The Almighty for mercy and forgiveness for your father and all deceased Muslims.
Allaah Knows best.