Reddit mentions of 100 Hikes in the Central Oregon Cascades

Yeah, the snow camping around here is great. I'd suggest picking up a copy of 100 Hikes in Oregon as a start. Once you hit August I recommend pretty much anywhere in the Three Sisters Wilderness for backpacking.

Honestly March is still ski season for me. If you are going to Eugene Spencer Butte wouldn't be what I would climb. I would go for Mt pisgah instead. That is going to have best views of thew mountains in that area. On a clear day you can see the three sisters.

Another thing you will be contending with is weather. It is very likely it will be cloudy and raining as well. It will be a good idea to have a backup so you can still go see something cool and not end up on a cloudy peak. You would missing quite the opportunity if you are in Salem and you don't go to silver falls state park. For the Salem area I would recommend picking up 100 hikes in the central Oregon Cascade. It has a lot of good trail suggestions plus the seasons that you are most likely able to hike them. Oregon Hikers is another fantastic resource and is pretty searchable with categories.

Another word of caution is you will legally need chains or traction tires (in your case I'm assuming chains since you are in a rental) in your car to go over passes. The snow zone requirement doesn't go away until the end of march. You can purchase a set of chains at Les Schwab and you can return them for a full refund if unused.