Mount Phelps is arguably the most distinctive peak visible when looking east towards the Cascades from the Seattle/Bellevue area--it is a dome-shaped fin that appears bulkier and slightly higher than the other frontal summits. The high peaks of the Cascade Crest such as Mount Daniel and Chimney Rock are too far away and hidden by the closer and less distinguished peaks such as Phelps.
The USGS topographic map incorrectly reverses the names of Mount Phelps and McClain Peaks. Fred Beckey, John Roper, and other noted local historians are very clear on this. This website does show Phelps in its correct location.
Climbing Mount Phelps involves a long dusty drive on the dirt North Fork Snoqualmie Road from North Bend and then a brushy climbers trail, bushwhack, and scramble to the summit. In early season there can be steep snow slopes. Despite their proximity and notable appearance from Seattle, Phelps and its nearby peaks are relatively far off the beaten path due to access issues.