For 3 gun in that area Kamloops is your best bet and even they have been slow of late (suspect the gun bans have played their part). KTSA actually have one listed on their site for September 10th but there hasn't been any activity with sign up etc so looking kinda bleak.....
Beyond that Abbotsford is probably the next closest.
Vernon actually has competitions for all 3 guns (pistol = IPSC / shotgun = combat shotgun which is this upcoming Sunday / rifle is service rifle) but not on the same day.