Hey my reply is a little late but I have a couple Columbian Spotted Frogs and thought I would chime in. Your set up sounds totally fine to me. These frogs are fairly aquatic and are excellent swimmers so a half land half water set up is ideal. Crickets is a good diet too (:

You definitely have an adult though, these frogs rarely get over 3" so yours is actually quite large. Does it have an orange pigment on the underside of its back legs? This is can be used to identify this species of frog and the orange color develops as the frogs age. However I have a recently transformed froglet which is already turning orange beneath, and my older CSF is almost entirely orange from his hind legs to his chin. Generally these frogs are a darker green or brown when they are very young, and lighten as they mature, but I'm sure coloring of CSF varies greatly in different areas. All adult CSFs I've seen around here in Montana have been a light brown/green with darker spots and bright orange hind legs.

These frogs are also almost silent and the males produce a quiet series of clicks as their mating call, so if you hear any loud croaking or other noises coming from your frog it is probably not a CSF.

It's usually not advised to handle frogs, especially those like CSF since they are capable of leaping large distances and can injure themselves if they fall from a large distance. However, I do handle my frogs to put them into their feeding containers and to clean out their tanks, so if you must that's okay, just be careful and make sure your hands are cupped securely around the frog to keep it from jumping away.

Rocks and gravel can be abrasive to a frog's delicate skin so I would consider removing the gravel and replacing it with some coconut fiber (EcoEarth). It looks pretty much like dirt and hold moisture well. If the frog accidentally eats some with its food it can be digested unlike moss and gravel which can kill your frog is accidentally eaten. In my frogs' tanks I pack the EcoEarth down hard so that it isn't loose in the cage. These frogs spend a lot of time in the water and if the substrate is too lose it will stick all over them (which probably isn't a problem for the frogs, but it gets messy).

Other than that I think you've got it! Goodluck (: