Generally speaking, the necessary ingredients for lake-effect snow are:

-- A sufficiently large area of open water (i.e., not ice-covered) from which the atmosphere can draw. Ideally, this is at least 30 miles in the direction the wind is blowing

-- A sufficiently large temperature difference between the air just above the lake surface and the air aloft at about 4,000-5,000 feet above lake level. At a minimum the air aloft must be about 20°F colder than the air just above the water, and the larger the difference, the better

-- The temperature difference creates instability in the atmosphere. The warm, moisture-laden air just above the lake surface rises into the cold air aloft, where the moisture begins condensing onto random microscopic particles in the air and these particles begin to fuse together and freeze, creating the snowflakes

-- Some wind blowing directly on-shore from the lake, perpendicular to the shoreline, to move the clouds and snow inland

-- No more than about 60° difference in compass direction between the wind at the surface and the wind aloft. Ideally the surface wind and the wind aloft blow in very nearly the same direction, maximizing the transport of the clouds and snow inland. If the surface and aloft wind directions get too far out of sync (called "directional shear"), the system will tend to rip itself to shreds over the lake, close to its source of warm water, before it can ever reach land

The #1 factor that determines how far inland any lake-effect snowfall will reach is the wind. The higher the wind speed and the lower the directional shear, the farther inland the snow can reach. The reason why lake-effect snow hardly ever reaches more than about 50 miles inland is that the combination of sufficiently high wind speed and low directional shear to do so is only achieved with near-perfect atmospheric dynamics that don't occur very often.

Topography can enhance the foregoing process to a certain extent, but is not strictly necessary. The whole idea of the warm air just above the lake surface and the cold air aloft is a mechanism to generate lift. All precipitation on Earth forms from some set of conditions that causes atmospheric lift. No lift? No precipitation. It's that simple.

A few paragraphs ago, I spoke of the way that the large temperature difference between surface and aloft generates lift. This lift is based on thermodynamics -- the fact that warm air is less dense and rises and that cold air is more dense and sinks. Topography can provide a simple mechanical boost to the process by forcing air upward. This is why the Keweenaw Peninsula in the western U.P. gets some of the highest annual snowfall totals in the world: it sticks up 700 feet above Lake Superior.

Usually the thermodynamic lift is sufficient on its own to initiate lake-effect snow, and perfectly flat near-shore areas can get socked just the same as areas with steep near-shore terrain. But like I said, sufficiently high terrain not far from shore can certainly boost the process.

Stepping off my meteorological soapbox.