If you're after a challenging and rewarding day hike with a view then Oyster Dome might be just right for you. Located in the Bellingham area right on the coast and neighboring Larabee State Park (one of our favorite State Parks on the Sound) you're going to get exciting views as you gain altitude along the few miles you'll have to travel to get to the top. You'll also have plenty of local eats and other water side parks and lakes to hike to while you're in the area.
Once you complete the trail you'll find yourself at the top of a massive cliff that overlooks the Puget Sound. That is of course assuming there aren't any low hanging clouds around... those may ruin your view in the non-summer months.
There are actually 2 different trailheads that will lead you to the top and a few trail intersections that will lead you in different directions so be prepared to read the signs at every junction so you end up where you were hoping to! There are some camping that fork off of this trail and lead you to Lilly and Lizard Lakes so this may be a good option for a pretty mild backpacking trip as well.
The easier trail begins on the eastern side and is located off the I5 Bow exit. (directions below) At the parking lot you'll find some bathrooms and typically a handful of lookout hunters after a pretty picture of the valley and coastline below. If you're there in good conditions you'll likely even get to see a hang glider/paraglider take off right from the parking lot. The takeoffs always draw a crowd so you'll be able to see them if they're up there.
The more challenging/steeper way to get to the top would be to begin near sea level on Chuckanut Road and hike all the extra switchbacks and milage through the trees and connect with the main trail later. This path is steeper and longer so be prepared for some calf pumping, quad burning hiking.
If you're really into making a fairly moderate hike as challenging and difficult as possible then you can always bring your rock climbing gear and multi-pitch your way straight up the Oyster Dome face! (If you don't know what a multi-pitch is then please don't try this) There are sport routes of varying difficulty all over the Oyster Dome, but I would refer you to one of the climbing shops located in Bellingham for details on routes, gear, and difficulty levels.
Bat Caves! I almost forgot to mention the Bat Caves. If you're not quite up for the full hike there are some bat caves at the bottom of the Oyster Dome and you can detour of the main trail (not far) to go explore the rocks and caves below. While you can poke your head in you'll likely run into the signs asking that you don't enter the caves. They're not super big, so I wouldn't let that detour you from trying this hike out. The main attraction is certainly the top and those cliff side views.
This is a popular hike on the weekends and you'll find plenty of college kids on the trails with Western WA University in the neighborhood. To avoid the crowd either get there early or try to make it up on a weekday. To be honest that goes for most trailheads located in the western half of our state.
Here are a few helpful links to get you started. Be sure to share your adventures/pictures on our Facebook Group.