According to the latest information available, the boat ramp named West Big Lake Boulevard 18421, Mount Vernon in Washington is a concrete boat ramp. It is approximately 12 feet wide and services Big Lake, which is a freshwater lake located in Skagit County.

The boat ramp is suitable for small to medium-sized boats and watercraft, including motorized and non-motorized boats. However, it is important to note that there may be restrictions on the use of certain types of watercraft, such as jet skis or personal watercraft.

Overall, the West Big Lake Boulevard 18421 boat ramp is a convenient access point for recreational boaters and fishermen looking to enjoy the pristine waters of Big Lake. It is well-maintained and provides easy access to the water, making it a popular spot for locals and visitors alike.