Andrews Glacier is a well-known Rocky Mountain National Park landmark, and is perhaps the only non-technical glacier (during certain times of the year) in the Park. It has more interest to climbers as a descent, but for beginners, it's a great place to "learn the ropes".
The glacier sees a massive influx of travelers during the height of the tourist season (June and July), when its slopes are fairly soft and low-angled, and it's not uncommon to see people in jeans and tennis shoes (very wet tennis shoes). By late summer and into the fall it turns to alpine ice, making crampons advisable, and after the first snow, avalanches can be a potential hazard. In winter, the snow can be either soft or wind-packed and the overall angle increases.
The center is the lowest-angled section with both sides being steeper. Later in the summer and into the fall, it's possible to avoid the snow and/or ice and go up or down the south (left) side. I've never done this, but I hear it can be a bit tricky depending on how much of the snow has melted.
If you need to protect it, pickets would work well.
Skinning up Andrews, Oct. 2013.
Andrews Tarn and the base of the glacier.
Looking down Andrews Glacier, with views of Andrew...
A view of the top of Andrews Glacier from the sout...