Pyramid Lake 

July 1, 2021. Ross Lake National Recreation Area, Whatcom County, Washington.
This hike might seem easy on the map, being a little over 2 miles one-way with 1500 feet of elevation change. But be aware it's pretty rough in spots (rocks and roots) and moderately steep in places too.
At this particular trailhead one does not need a Northwest Forest Pass or any other permit to park and hike to the lake. However there is no camping allowed anywhere along this trail.