I have nothing bad to say about this park, it just wasn't my cup of tea. The main trails are sandy and run along the Potomac and offer nice views, but because there aren't many large trees by the trail, there's not much shade! So you'll want to make sure you lather up the sunscreen, even if it doesn't seem that hot and sunny outside...something about the sandy path and the reflection of the Potomac seems to lead to sunburn! What I will say is that if you are a birdwatcher you've come to the right place. I visited in early April and saw two nesting bald eagles and two nesting osprey. I saw a bunch of other birds, but I'm not sure what kind there were. Another thing to keep in mind is that there were snakes! We ran into a large black one and while I don't think it was poisonous or dangerous, it could be scary for those who are scared of snakes. Because the eagles and osprey are nesting, half the park is closed. However, if you have a decent camera with a good zoom, you should be able to get good pictures of the eagles and osprey from the portion of the park that is open. The main trails are boarded on one side by the Potomac and on the other side by wetlands. It was relatively empty when I visited and seems to be one of the lesser visited parks in the area.
And one last thing! The toilets have no running water and don't exactly smell great, so you may want to go to the bathroom before you leave home!