Hi Sara, your insect is called a gooseberry sawfly or sometimes also called the imported currantworm, they feed on currants and gooseberries. These are not native but have been introduced with ornamental currants/gooseberries and are very common in Anchorage now. Starting a bit earlier in June I like to check all my leaves on my plants every few days looking for small holes or for eggs along the ribs on the underside of the leaves. Those leaves can just be plucked off. Once the larvae get a bit larger like in your photo they can be a bit more work to manage, but shaking them off the plant into a container to dispose of them and plucking any heavily infested leaves does work.

There are pesticide options that are effective but these are typically most effective when the larvae are still small. You can find good information about those options here: https://extension.umn.edu/yard-and-garden-insects/sawflies#pick-sawflies-off-plants-1113862

While these insects are very caterpillar-like just keep in mind that technically they are not truly caterpillars, they are sawfly larvae, so just be aware that products containing the active ingredient Bacillus thuringiensis kurstaki (aka 'Btk') are not effective on this insect.